646516525 has 24 divisors (see below), whose sum is σ = 819489960. Its totient is φ = 505789440.

The previous prime is 646516489. The next prime is 646516547. The reversal of 646516525 is 525615646.

It can be written as a sum of positive squares in 12 ways, for example, as 18412681 + 628103844 = 4291^2 + 25062^2 .

It is not a de Polignac number, because 646516525 - 2¹³ = 646508333 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 541329 + ... + 542521.

It is an arithmetic number, because the mean of its divisors is an integer number (34145415).

Almost surely, 2^646516525 is an apocalyptic number.

It is an amenable number.

646516525 is a deficient number, since it is larger than the sum of its proper divisors (172973435).

646516525 is a wasteful number, since it uses less digits than its factorization.

646516525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1665 (or 1660 counting only the distinct ones).

The product of its digits is 216000, while the sum is 40.

The square root of 646516525 is about 25426.6892260868. The cubic root of 646516525 is about 864.6888854084.

The spelling of 646516525 in words is "six hundred forty-six million, five hundred sixteen thousand, five hundred twenty-five".