231311212121220 has 96 divisors (see below), whose sum is σ = 807486413239296. Its totient is φ = 48064667452800.

The previous prime is 231311212121201. The next prime is 231311212121233. The reversal of 231311212121220 is 22121212113132.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25033676346 + ... + 25033685585.

It is an arithmetic number, because the mean of its divisors is an integer number (8411316804576).

Almost surely, 2^{231311212121220} is an apocalyptic number.

231311212121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231311212121220 is an abundant number, since it is smaller than the sum of its proper divisors (576175201118076).

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

231311212121220 is a wasteful number, since it uses less digits than its factorization.

231311212121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50067361961 (or 50067361959 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

Adding to 231311212121220 its reverse (22121212113132), we get a palindrome (253432424234352).

The spelling of 231311212121220 in words is "two hundred thirty-one trillion, three hundred eleven billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty".