191231994774 has 32 divisors (see below), whose sum is σ = 389207990880. Its totient is φ = 62622547200.

The previous prime is 191231994761. The next prime is 191231994781. The reversal of 191231994774 is 477499132191.

It is a super-2 number, since 2×191231994774² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17719 + ... + 618690.

It is an arithmetic number, because the mean of its divisors is an integer number (12162749715).

Almost surely, 2^191231994774 is an apocalyptic number.

191231994774 is an abundant number, since it is smaller than the sum of its proper divisors (197975996106).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

191231994774 is a wasteful number, since it uses less digits than its factorization.

191231994774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637296.

The product of its digits is 3429216, while the sum is 57.

The spelling of 191231994774 in words is "one hundred ninety-one billion, two hundred thirty-one million, nine hundred ninety-four thousand, seven hundred seventy-four".