131993865 has 24 divisors (see below), whose sum is σ = 242248968. Its totient is φ = 66255360.

The previous prime is 131993857. The next prime is 131993867. The reversal of 131993865 is 568399131.

It can be written as a sum of positive squares in 4 ways, for example, as 24000201 + 107993664 = 4899^2 + 10392^2 .

It is not a de Polignac number, because 131993865 - 2³ = 131993857 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 131993865.

It is not an unprimeable number, because it can be changed into a prime (131993867) 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 23 ways as a sum of consecutive naturals, for example, 85506 + ... + 87035.

It is an arithmetic number, because the mean of its divisors is an integer number (10093707).

Almost surely, 2^131993865 is an apocalyptic number.

131993865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

131993865 is a deficient number, since it is larger than the sum of its proper divisors (110255103).

131993865 is a wasteful number, since it uses less digits than its factorization.

131993865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172569 (or 172566 counting only the distinct ones).

The product of its digits is 174960, while the sum is 45.

The square root of 131993865 is about 11488.8582983689. The cubic root of 131993865 is about 509.1564486538.

The spelling of 131993865 in words is "one hundred thirty-one million, nine hundred ninety-three thousand, eight hundred sixty-five".