131861520 has 560 divisors, whose sum is σ = 585498240. Its totient is φ = 26873856.

The previous prime is 131861497. The next prime is 131861531. The reversal of 131861520 is 25168131.

131861520 is a `hidden beast` number, since 13 + 18 + 615 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (560).

It is a Harshad number since it is a multiple of its sum of digits (27).

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 111 ways as a sum of consecutive naturals, for example, 6940071 + ... + 6940089.

Almost surely, 2^131861520 is an apocalyptic number.

131861520 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 131861520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292749120).

131861520 is an abundant number, since it is smaller than the sum of its proper divisors (453636720).

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

131861520 is a wasteful number, since it uses less digits than its factorization.

131861520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 131861520 is about 11483.0971431927. The cubic root of 131861520 is about 508.9862214392.

It can be divided in two parts, 13186 and 1520, that added together give a triangular number (14706 = T₁₇₁).

The spelling of 131861520 in words is "one hundred thirty-one million, eight hundred sixty-one thousand, five hundred twenty".