1231311311220 has 48 divisors (see below), whose sum is σ = 3448040920128. Its totient is φ = 328314516480.

The previous prime is 1231311311183. The next prime is 1231311311281. The reversal of 1231311311220 is 221131131321.

It is a super-2 number, since 2×1231311311220² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 531646 + ... + 1656885.

It is an arithmetic number, because the mean of its divisors is an integer number (71834185836).

Almost surely, 2^{1231311311220} is an apocalyptic number.

1231311311220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1231311311220 is an abundant number, since it is smaller than the sum of its proper divisors (2216729608908).

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

1231311311220 is a wasteful number, since it uses less digits than its factorization.

1231311311220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2197920 (or 2197918 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

Adding to 1231311311220 its reverse (221131131321), we get a palindrome (1452442442541).

The spelling of 1231311311220 in words is "one trillion, two hundred thirty-one billion, three hundred eleven million, three hundred eleven thousand, two hundred twenty".