646430625 has 75 divisors (see below), whose sum is σ = 1217456383. Its totient is φ = 341712000.

The previous prime is 646430591. The next prime is 646430639. The reversal of 646430625 is 526034646.

646430625 = 1³ + 2³ + ... + 225³.

The square root of 646430625 is 25425.

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

646430625 is a `hidden beast` number, since 6 + 4 + 643 + 0 + 6 + 2 + 5 = 666.

It can be written as a sum of positive squares in 7 ways, for example, as 631868769 + 14561856 = 25137^2 + 3816^2 .

It is a tau number, because it is divible by the number of its divisors (75).

It is not a de Polignac number, because 646430625 - 2¹¹ = 646428577 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 646430625.

It is an unprimeable number.

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 74 ways as a sum of consecutive naturals, for example, 5720569 + ... + 5720681.

Almost surely, 2^646430625 is an apocalyptic number.

646430625 is the 25425-th square number.

646430625 is the 12713-rd centered octagonal number.

It is an amenable number.

646430625 is a deficient number, since it is larger than the sum of its proper divisors (571025758).

646430625 is an frugal number, since it uses more digits than its factorization.

646430625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The cubic root of 646430625 is about 864.6505878232.

Multiplying 646430625 by its sum of digits (36), we get a square (23271502500 = 152550²).

The spelling of 646430625 in words is "six hundred forty-six million, four hundred thirty thousand, six hundred twenty-five".