64400625 has 45 divisors (see below), whose sum is σ = 117338221. Its totient is φ = 34026000.

The previous prime is 64400617. The next prime is 64400659. The reversal of 64400625 is 52600446.

It is a happy number.

The square root of 64400625 is 8025.

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

It can be written as a sum of positive squares in 2 ways, for example, as 5049009 + 59351616 = 2247^2 + 7704^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 64400625 - 2³ = 64400617 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 601822 + ... + 601928.

Almost surely, 2^64400625 is an apocalyptic number.

64400625 is the 8025-th square number.

64400625 is the 4013-rd centered octagonal number.

It is an amenable number.

64400625 is a deficient number, since it is larger than the sum of its proper divisors (52937596).

64400625 is an equidigital number, since it uses as much as digits as its factorization.

64400625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The cubic root of 64400625 is about 400.8328999073.

It can be divided in two parts, 64400 and 625, that added together give a square (65025 = 255²).

The spelling of 64400625 in words is "sixty-four million, four hundred thousand, six hundred twenty-five".