85725173746521 has 27 divisors (see below), whose sum is σ = 124477941085407. Its totient is φ = 56850445866240.

The previous prime is 85725173746463. The next prime is 85725173746529. The reversal of 85725173746521 is 12564737152758.

The square root of 85725173746521 is 9258789.

It is a perfect power (a square), and thus also a powerful number.

85725173746521 is a `hidden beast` number, since 8 + 5 + 7 + 2 + 517 + 37 + 4 + 65 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20770213779225 + 64954959967296 = 4557435^2 + 8059464^2 .

It is not a de Polignac number, because 85725173746521 - 2⁷ = 85725173746393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (85725173746529) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 5360830836 + ... + 5360846826.

Almost surely, 2^{85725173746521} is an apocalyptic number.

85725173746521 is the 9258789-th square number.

85725173746521 is the 4629395-th centered octagonal number.

It is an amenable number.

85725173746521 is a deficient number, since it is larger than the sum of its proper divisors (38752767338886).

85725173746521 is an frugal number, since it uses more digits than its factorization.

85725173746521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32374 (or 16187 counting only the distinct ones).

The product of its digits is 98784000, while the sum is 63.

The spelling of 85725173746521 in words is "eighty-five trillion, seven hundred twenty-five billion, one hundred seventy-three million, seven hundred forty-six thousand, five hundred twenty-one".