133931520 has 120 divisors (see below), whose sum is σ = 463922316. Its totient is φ = 35708928.

The previous prime is 133931503. The next prime is 133931521. The reversal of 133931520 is 25139331.

It is a happy number.

133931520 is a `hidden beast` number, since 133 + 9 + 3 + 1 + 520 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 133818624 + 112896 = 11568^2 + 336^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (133931521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20134 + ... + 25946.

Almost surely, 2^133931520 is an apocalyptic number.

133931520 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 133931520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (231961158).

133931520 is an abundant number, since it is smaller than the sum of its proper divisors (329990796).

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

133931520 is an equidigital number, since it uses as much as digits as its factorization.

133931520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5842 (or 5823 counting only the distinct ones).

The product of its (nonzero) digits is 2430, while the sum is 27.

The square root of 133931520 is about 11572.8786393015. The cubic root of 133931520 is about 511.6358087165.

The spelling of 133931520 in words is "one hundred thirty-three million, nine hundred thirty-one thousand, five hundred twenty".