131566515661021 has 32 divisors (see below), whose sum is σ = 151964146817280. Its totient is φ = 111571193664000.

The previous prime is 131566515661019. The next prime is 131566515661027. The reversal of 131566515661021 is 120166515665131.

It is not a de Polignac number, because 131566515661021 - 2¹ = 131566515661019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131566515661027) 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, 5940591070 + ... + 5940613216.

It is an arithmetic number, because the mean of its divisors is an integer number (4748879588040).

Almost surely, 2^{131566515661021} is an apocalyptic number.

It is an amenable number.

131566515661021 is a deficient number, since it is larger than the sum of its proper divisors (20397631156259).

131566515661021 is a wasteful number, since it uses less digits than its factorization.

131566515661021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28165.

The product of its (nonzero) digits is 972000, while the sum is 49.

The spelling of 131566515661021 in words is "one hundred thirty-one trillion, five hundred sixty-six billion, five hundred fifteen million, six hundred sixty-one thousand, twenty-one".