191431920 has 40 divisors (see below), whose sum is σ = 593439696. Its totient is φ = 51048448.

The previous prime is 191431909. The next prime is 191431963. The reversal of 191431920 is 29134191.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 398577 + ... + 399056.

Almost surely, 2^191431920 is an apocalyptic number.

191431920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191431920 is an abundant number, since it is smaller than the sum of its proper divisors (402007776).

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

191431920 is a wasteful number, since it uses less digits than its factorization.

191431920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 797649 (or 797643 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 191431920 is about 13835.8924540486. The cubic root of 191431920 is about 576.3302985991.

The spelling of 191431920 in words is "one hundred ninety-one million, four hundred thirty-one thousand, nine hundred twenty".