525617721 has 16 divisors (see below), whose sum is σ = 805545600. Its totient is φ = 338328144.

The previous prime is 525617699. The next prime is 525617723. The reversal of 525617721 is 127716525.

525617721 is a `hidden beast` number, since 5 + 2 + 561 + 77 + 21 = 666.

It is not a de Polignac number, because 525617721 - 2¹⁰ = 525616697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (525617723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 334861 + ... + 336426.

It is an arithmetic number, because the mean of its divisors is an integer number (50346600).

Almost surely, 2^525617721 is an apocalyptic number.

It is an amenable number.

525617721 is a deficient number, since it is larger than the sum of its proper divisors (279927879).

525617721 is a wasteful number, since it uses less digits than its factorization.

525617721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671325 (or 671319 counting only the distinct ones).

The product of its digits is 29400, while the sum is 36.

The square root of 525617721 is about 22926.3542893326. The cubic root of 525617721 is about 807.0305954321.

The spelling of 525617721 in words is "five hundred twenty-five million, six hundred seventeen thousand, seven hundred twenty-one".