191231520 has 96 divisors (see below), whose sum is σ = 607315968. Its totient is φ = 50577408.

The previous prime is 191231519. The next prime is 191231527. The reversal of 191231520 is 25132191.

191231520 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 (96).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (191231527) 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, 59392 + ... + 62528.

It is an arithmetic number, because the mean of its divisors is an integer number (6326208).

Almost surely, 2^191231520 is an apocalyptic number.

191231520 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 191231520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303657984).

191231520 is an abundant number, since it is smaller than the sum of its proper divisors (416084448).

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

191231520 is a wasteful number, since it uses less digits than its factorization.

191231520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3282 (or 3274 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 24.

The square root of 191231520 is about 13828.6485239882. The cubic root of 191231520 is about 576.1291184307.

The spelling of 191231520 in words is "one hundred ninety-one million, two hundred thirty-one thousand, five hundred twenty".