191971920 has 80 divisors (see below), whose sum is σ = 680135040. Its totient is φ = 43878912.

The previous prime is 191971861. The next prime is 191971931. The reversal of 191971920 is 29179191.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55455 + ... + 58814.

It is an arithmetic number, because the mean of its divisors is an integer number (8501688).

Almost surely, 2^191971920 is an apocalyptic number.

191971920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

191971920 is an abundant number, since it is smaller than the sum of its proper divisors (488163120).

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

191971920 is a wasteful number, since it uses less digits than its factorization.

191971920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114292 (or 114286 counting only the distinct ones).

The product of its (nonzero) digits is 10206, while the sum is 39.

The square root of 191971920 is about 13855.3931737789. The cubic root of 191971920 is about 576.8717028852.

The spelling of 191971920 in words is "one hundred ninety-one million, nine hundred seventy-one thousand, nine hundred twenty".