85904021 has 4 divisors (see below), whose sum is σ = 98176032. Its totient is φ = 73632012.

The previous prime is 85903999. The next prime is 85904023. The reversal of 85904021 is 12040958.

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 85904021 - 2²² = 81709717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85904023) 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, 6135995 + ... + 6136008.

It is an arithmetic number, because the mean of its divisors is an integer number (24544008).

Almost surely, 2^85904021 is an apocalyptic number.

It is an amenable number.

85904021 is a deficient number, since it is larger than the sum of its proper divisors (12272011).

85904021 is a wasteful number, since it uses less digits than its factorization.

85904021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12272010.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 85904021 is about 9268.4422099941. The cubic root of 85904021 is about 441.2362290026.

Adding to 85904021 its reverse (12040958), we get a palindrome (97944979).

The spelling of 85904021 in words is "eighty-five million, nine hundred four thousand, twenty-one".