31213200133121 has 4 divisors (see below), whose sum is σ = 31724891938644. Its totient is φ = 30701508327600.

The previous prime is 31213200133117. The next prime is 31213200133183. The reversal of 31213200133121 is 12133100231213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 12913960960000 + 18299239173121 = 3593600^2 + 4277761^2 .

It is a cyclic number.

It is not a de Polignac number, because 31213200133121 - 2² = 31213200133117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31213200133421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255845902670 + ... + 255845902791.

It is an arithmetic number, because the mean of its divisors is an integer number (7931222984661).

Almost surely, 2^{31213200133121} is an apocalyptic number.

It is an amenable number.

31213200133121 is a deficient number, since it is larger than the sum of its proper divisors (511691805523).

31213200133121 is an equidigital number, since it uses as much as digits as its factorization.

31213200133121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511691805522.

The product of its (nonzero) digits is 648, while the sum is 23.

Adding to 31213200133121 its reverse (12133100231213), we get a palindrome (43346300364334).

The spelling of 31213200133121 in words is "thirty-one trillion, two hundred thirteen billion, two hundred million, one hundred thirty-three thousand, one hundred twenty-one".