91979490842 has 4 divisors (see below), whose sum is σ = 137969236266. Its totient is φ = 45989745420.

The previous prime is 91979490833. The next prime is 91979490859. The reversal of 91979490842 is 24809497919.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 24809497919 = 491 ⋅50528509.

It can be written as a sum of positive squares in only one way, i.e., 90209521801 + 1769969041 = 300349^2 + 42071^2 .

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 22994872709 + ... + 22994872712.

Almost surely, 2^91979490842 is an apocalyptic number.

91979490842 is a deficient number, since it is larger than the sum of its proper divisors (45989745424).

91979490842 is a wasteful number, since it uses less digits than its factorization.

91979490842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45989745423.

The product of its (nonzero) digits is 11757312, while the sum is 62.

The spelling of 91979490842 in words is "ninety-one billion, nine hundred seventy-nine million, four hundred ninety thousand, eight hundred forty-two".