85617521 has 4 divisors (see below), whose sum is σ = 93400944. Its totient is φ = 77834100.

The previous prime is 85617517. The next prime is 85617529. The reversal of 85617521 is 12571658.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 85617521 - 2² = 85617517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85617529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3891695 + ... + 3891716.

It is an arithmetic number, because the mean of its divisors is an integer number (23350236).

Almost surely, 2^85617521 is an apocalyptic number.

It is an amenable number.

85617521 is a deficient number, since it is larger than the sum of its proper divisors (7783423).

85617521 is a wasteful number, since it uses less digits than its factorization.

85617521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7783422.

The product of its digits is 16800, while the sum is 35.

The square root of 85617521 is about 9252.9736301364. The cubic root of 85617521 is about 440.7451577873.

The spelling of 85617521 in words is "eighty-five million, six hundred seventeen thousand, five hundred twenty-one".