131221375401220 has 24 divisors (see below), whose sum is σ = 296762187446424. Its totient is φ = 48450969378816.

The previous prime is 131221375401217. The next prime is 131221375401223. The reversal of 131221375401220 is 22104573122131.

It is an interprime number because it is at equal distance from previous prime (131221375401217) and next prime (131221375401223).

It can be written as a sum of positive squares in 4 ways, for example, as 20838111154884 + 110383264246336 = 4564878^2 + 10506344^2 .

It is not an unprimeable number, because it can be changed into a prime (131221375401223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 252348798589 + ... + 252348799108.

It is an arithmetic number, because the mean of its divisors is an integer number (12365091143601).

Almost surely, 2^{131221375401220} is an apocalyptic number.

131221375401220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131221375401220 is an abundant number, since it is smaller than the sum of its proper divisors (165540812045204).

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

131221375401220 is a wasteful number, since it uses less digits than its factorization.

131221375401220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504697597719 (or 504697597717 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 34.

The spelling of 131221375401220 in words is "one hundred thirty-one trillion, two hundred twenty-one billion, three hundred seventy-five million, four hundred one thousand, two hundred twenty".