85901611991 has 4 divisors (see below), whose sum is σ = 92509428312. Its totient is φ = 79293795672.

The previous prime is 85901611969. The next prime is 85901612021. The reversal of 85901611991 is 19911610958.

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

It is not a de Polignac number, because 85901611991 - 2¹⁰ = 85901610967 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 (85901611931) 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, 3303908141 + ... + 3303908166.

It is an arithmetic number, because the mean of its divisors is an integer number (23127357078).

Almost surely, 2^85901611991 is an apocalyptic number.

85901611991 is a deficient number, since it is larger than the sum of its proper divisors (6607816321).

85901611991 is a wasteful number, since it uses less digits than its factorization.

85901611991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6607816320.

The product of its (nonzero) digits is 174960, while the sum is 50.

The spelling of 85901611991 in words is "eighty-five billion, nine hundred one million, six hundred eleven thousand, nine hundred ninety-one".