8517220525 has 24 divisors (see below), whose sum is σ = 11529244224. Its totient is φ = 6190166400.

The previous prime is 8517220477. The next prime is 8517220549. The reversal of 8517220525 is 5250227158.

It is a de Polignac number, because none of the positive numbers 2^k-8517220525 is a prime.

It is a Duffinian number.

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, 432289 + ... + 451561.

It is an arithmetic number, because the mean of its divisors is an integer number (480385176).

Almost surely, 2^8517220525 is an apocalyptic number.

It is an amenable number.

8517220525 is a deficient number, since it is larger than the sum of its proper divisors (3012023699).

8517220525 is a wasteful number, since it uses less digits than its factorization.

8517220525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20901 (or 20896 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 37.

The square root of 8517220525 is about 92288.7887286424. The cubic root of 8517220525 is about 2042.2048221428.

The spelling of 8517220525 in words is "eight billion, five hundred seventeen million, two hundred twenty thousand, five hundred twenty-five".