521656325 has 18 divisors (see below), whose sum is σ = 663068982. Its totient is φ = 407113600.

The previous prime is 521656319. The next prime is 521656327. The reversal of 521656325 is 523656125.

It can be written as a sum of positive squares in 9 ways, for example, as 453775204 + 67881121 = 21302^2 + 8239^2 .

It is not a de Polignac number, because 521656325 - 2¹⁰ = 521655301 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521656327) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 35819 + ... + 48231.

Almost surely, 2^521656325 is an apocalyptic number.

It is an amenable number.

521656325 is a deficient number, since it is larger than the sum of its proper divisors (141412657).

521656325 is a wasteful number, since it uses less digits than its factorization.

521656325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12505 (or 12459 counting only the distinct ones).

The product of its digits is 54000, while the sum is 35.

The square root of 521656325 is about 22839.7969561903. The cubic root of 521656325 is about 804.9980453382.

The spelling of 521656325 in words is "five hundred twenty-one million, six hundred fifty-six thousand, three hundred twenty-five".