191857920 has 144 divisors (see below), whose sum is σ = 649010880. Its totient is φ = 48136192.

The previous prime is 191857891. The next prime is 191857921. The reversal of 191857920 is 29758191.

It is a super-2 number, since 2×191857920² = 73618922933452800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191857921) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63811 + ... + 66749.

It is an arithmetic number, because the mean of its divisors is an integer number (4507020).

Almost surely, 2^191857920 is an apocalyptic number.

191857920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 191857920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (324505440).

191857920 is an abundant number, since it is smaller than the sum of its proper divisors (457152960).

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

191857920 is a wasteful number, since it uses less digits than its factorization.

191857920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2980 (or 2966 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 42.

The square root of 191857920 is about 13851.2786413385. The cubic root of 191857920 is about 576.7574910498.

The spelling of 191857920 in words is "one hundred ninety-one million, eight hundred fifty-seven thousand, nine hundred twenty".