2639390625 has 63 divisors (see below), whose sum is σ = 4800544021. Its totient is φ = 1397400000.

The previous prime is 2639390549. The next prime is 2639390627. The reversal of 2639390625 is 5260939362.

The square root of 2639390625 is 51375.

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

2639390625 is a `hidden beast` number, since 2 + 639 + 3 + 9 + 0 + 6 + 2 + 5 = 666.

It can be written as a sum of positive squares in 10 ways, for example, as 2349437841 + 289952784 = 48471^2 + 17028^2 .

It is not a de Polignac number, because 2639390625 - 2¹³ = 2639382433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2639390627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 19265557 + ... + 19265693.

Almost surely, 2^2639390625 is an apocalyptic number.

2639390625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2639390625 is the 51375-th square number.

2639390625 is the 25688-th centered octagonal number.

It is an amenable number.

2639390625 is a deficient number, since it is larger than the sum of its proper divisors (2161153396).

2639390625 is an frugal number, since it uses more digits than its factorization.

2639390625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 310 (or 145 counting only the distinct ones).

The product of its (nonzero) digits is 524880, while the sum is 45.

The cubic root of 2639390625 is about 1381.9782984467.

The spelling of 2639390625 in words is "two billion, six hundred thirty-nine million, three hundred ninety thousand, six hundred twenty-five".