528632721 has 24 divisors (see below), whose sum is σ = 787989384. Its totient is φ = 341283840.

The previous prime is 528632719. The next prime is 528632723. The reversal of 528632721 is 127236825.

528632721 is a `hidden beast` number, since 528 + 63 + 2 + 72 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (528632719) and next prime (528632723).

It can be written as a sum of positive squares in 4 ways, for example, as 76475025 + 452157696 = 8745^2 + 21264^2 .

It is not a de Polignac number, because 528632721 - 2¹ = 528632719 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (528632723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45325 + ... + 55781.

It is an arithmetic number, because the mean of its divisors is an integer number (32832891).

Almost surely, 2^528632721 is an apocalyptic number.

It is an amenable number.

528632721 is a deficient number, since it is larger than the sum of its proper divisors (259356663).

528632721 is a wasteful number, since it uses less digits than its factorization.

528632721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10641 (or 10638 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 528632721 is about 22992.0142875738. The cubic root of 528632721 is about 808.5707259343.

The spelling of 528632721 in words is "five hundred twenty-eight million, six hundred thirty-two thousand, seven hundred twenty-one".