90785979391 has 4 divisors (see below), whose sum is σ = 90787494312. Its totient is φ = 90784464472.

The previous prime is 90785979353. The next prime is 90785979397. The reversal of 90785979391 is 19397958709.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19397958709 = 23753 ⋅816653.

It is a cyclic number.

It is not a de Polignac number, because 90785979391 - 2¹¹ = 90785977343 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 (90785979397) 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, 663700 + ... + 788713.

It is an arithmetic number, because the mean of its divisors is an integer number (22696873578).

Almost surely, 2^90785979391 is an apocalyptic number.

90785979391 is a deficient number, since it is larger than the sum of its proper divisors (1514921).

90785979391 is a wasteful number, since it uses less digits than its factorization.

90785979391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1514920.

The product of its (nonzero) digits is 38578680, while the sum is 67.

The spelling of 90785979391 in words is "ninety billion, seven hundred eighty-five million, nine hundred seventy-nine thousand, three hundred ninety-one".