85220831 has 4 divisors (see below), whose sum is σ = 86247672. Its totient is φ = 84193992.

The previous prime is 85220791. The next prime is 85220867. The reversal of 85220831 is 13802258.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 85220831 - 2²² = 81026527 is a prime.

It is a super-2 number, since 2×85220831² = 14525180072661122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85220794 and 85220803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85210831) 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, 513296 + ... + 513461.

It is an arithmetic number, because the mean of its divisors is an integer number (21561918).

Almost surely, 2^85220831 is an apocalyptic number.

85220831 is a deficient number, since it is larger than the sum of its proper divisors (1026841).

85220831 is a wasteful number, since it uses less digits than its factorization.

85220831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1026840.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 85220831 is about 9231.5129312589. The cubic root of 85220831 is about 440.0634051189.

The spelling of 85220831 in words is "eighty-five million, two hundred twenty thousand, eight hundred thirty-one".