1550390625 has 135 divisors (see below), whose sum is σ = 3367674057. Its totient is φ = 708750000.

The previous prime is 1550390581. The next prime is 1550390629. The reversal of 1550390625 is 5260930551.

The square root of 1550390625 is 39375.

It is a perfect power (a square), and thus also a powerful number.

1550390625 is a `hidden beast` number, since 1 + 5 + 503 + 90 + 62 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1102306401 + 448084224 = 33201^2 + 21168^2 .

It is a tau number, because it is divible by the number of its divisors (135).

It is not a de Polignac number, because 1550390625 - 2¹⁷ = 1550259553 is a prime.

It is a super-2 number, since 2×1550390625² = 4807422180175781250, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1550390625.

It is not an unprimeable number, because it can be changed into a prime (1550390629) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 221484372 + ... + 221484378.

Almost surely, 2^1550390625 is an apocalyptic number.

1550390625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1550390625 is the 39375-th square number.

1550390625 is the 19688-th centered octagonal number.

It is an amenable number.

1550390625 is an abundant number, since it is smaller than the sum of its proper divisors (1817283432).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1550390625 is an frugal number, since it uses more digits than its factorization.

1550390625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66 (or 15 counting only the distinct ones).

The product of its (nonzero) digits is 40500, while the sum is 36.

The cubic root of 1550390625 is about 1157.3917380595.

Multiplying 1550390625 by its sum of digits (36), we get a square (55814062500 = 236250²).

The spelling of 1550390625 in words is "one billion, five hundred fifty million, three hundred ninety thousand, six hundred twenty-five".