1625617440 has 72 divisors (see below), whose sum is σ = 5547424428. Its totient is φ = 433497600.

The previous prime is 1625617421. The next prime is 1625617481. The reversal of 1625617440 is 447165261.

1625617440 is a `hidden beast` number, since 16 + 25 + 617 + 4 + 4 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1559618064 + 65999376 = 39492^2 + 8124^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×1625617440² = 5285264122464307200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1625617395 and 1625617404.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 563011 + ... + 565890.

Almost surely, 2^1625617440 is an apocalyptic number.

1625617440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1625617440 is an abundant number, since it is smaller than the sum of its proper divisors (3921806988).

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

1625617440 is a wasteful number, since it uses less digits than its factorization.

1625617440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128922 (or 1128911 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The square root of 1625617440 is about 40318.9464148060. The cubic root of 1625617440 is about 1175.8162283989.

The spelling of 1625617440 in words is "one billion, six hundred twenty-five million, six hundred seventeen thousand, four hundred forty".