85991947691 has 16 divisors (see below), whose sum is σ = 94812157440. Its totient is φ = 77488820640.

The previous prime is 85991947681. The next prime is 85991947697. The reversal of 85991947691 is 19674919958.

It is a cyclic number.

It is not a de Polignac number, because 85991947691 - 2³⁴ = 68812078507 is a prime.

It is not an unprimeable number, because it can be changed into a prime (85991947697) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1004780 + ... + 1086998.

It is an arithmetic number, because the mean of its divisors is an integer number (5925759840).

Almost surely, 2^85991947691 is an apocalyptic number.

85991947691 is a deficient number, since it is larger than the sum of its proper divisors (8820209749).

85991947691 is a wasteful number, since it uses less digits than its factorization.

85991947691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84146.

The product of its digits is 44089920, while the sum is 68.

The spelling of 85991947691 in words is "eighty-five billion, nine hundred ninety-one million, nine hundred forty-seven thousand, six hundred ninety-one".