191291223920 has 20 divisors (see below), whose sum is σ = 444752095800. Its totient is φ = 76516489536.

The previous prime is 191291223911. The next prime is 191291223943. The reversal of 191291223920 is 29322192191.

191291223920 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

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 in 3 ways as a sum of consecutive naturals, for example, 1195570070 + ... + 1195570229.

It is an arithmetic number, because the mean of its divisors is an integer number (22237604790).

Almost surely, 2^191291223920 is an apocalyptic number.

191291223920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191291223920 is an abundant number, since it is smaller than the sum of its proper divisors (253460871880).

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

191291223920 is a wasteful number, since it uses less digits than its factorization.

191291223920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2391140312 (or 2391140306 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 41.

The spelling of 191291223920 in words is "one hundred ninety-one billion, two hundred ninety-one million, two hundred twenty-three thousand, nine hundred twenty".