85981431 has 4 divisors (see below), whose sum is σ = 114641912. Its totient is φ = 57320952.

The previous prime is 85981417. The next prime is 85981439. The reversal of 85981431 is 13418958.

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

It is not a de Polignac number, because 85981431 - 2²¹ = 83884279 is a prime.

It is a super-2 number, since 2×85981431² = 14785612953615522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 85981431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85981439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14330236 + ... + 14330241.

It is an arithmetic number, because the mean of its divisors is an integer number (28660478).

Almost surely, 2^85981431 is an apocalyptic number.

85981431 is a deficient number, since it is larger than the sum of its proper divisors (28660481).

85981431 is a wasteful number, since it uses less digits than its factorization.

85981431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28660480.

The product of its digits is 34560, while the sum is 39.

The square root of 85981431 is about 9272.6172680641. The cubic root of 85981431 is about 441.3687250977.

The spelling of 85981431 in words is "eighty-five million, nine hundred eighty-one thousand, four hundred thirty-one".