131561045 has 32 divisors (see below), whose sum is σ = 208417536. Its totient is φ = 77184000.

The previous prime is 131561033. The next prime is 131561047. The reversal of 131561045 is 540165131.

It is not a de Polignac number, because 131561045 - 2⁴ = 131561029 is a prime.

It is a super-2 number, since 2×131561045² = 34616617122984050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131561047) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3506 + ... + 16595.

It is an arithmetic number, because the mean of its divisors is an integer number (6513048).

Almost surely, 2^131561045 is an apocalyptic number.

It is an amenable number.

131561045 is a deficient number, since it is larger than the sum of its proper divisors (76856491).

131561045 is a wasteful number, since it uses less digits than its factorization.

131561045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20141.

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 131561045 is about 11470.0063208352. The cubic root of 131561045 is about 508.5993156679.

The spelling of 131561045 in words is "one hundred thirty-one million, five hundred sixty-one thousand, forty-five".