131221230100 has 36 divisors (see below), whose sum is σ = 287569399068. Its totient is φ = 51968800000.

The previous prime is 131221230083. The next prime is 131221230109. The reversal of 131221230100 is 1032122131.

It can be written as a sum of positive squares in 6 ways, for example, as 2539756816 + 128681473284 = 50396^2 + 358722^2 .

It is a super-2 number, since 2×131221230100² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221230109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6486001 + ... + 6506200.

It is an arithmetic number, because the mean of its divisors is an integer number (7988038863).

Almost surely, 2^131221230100 is an apocalyptic number.

131221230100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

131221230100 is an abundant number, since it is smaller than the sum of its proper divisors (156348168968).

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

131221230100 is a wasteful number, since it uses less digits than its factorization.

131221230100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12992316 (or 12992309 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 131221230100 its reverse (1032122131), we get a palindrome (132253352231).

The spelling of 131221230100 in words is "one hundred thirty-one billion, two hundred twenty-one million, two hundred thirty thousand, one hundred".