2131231111220 has 24 divisors (see below), whose sum is σ = 4525872813000. Its totient is φ = 842913876992.

The previous prime is 2131231111211. The next prime is 2131231111307. The reversal of 2131231111220 is 221111321312.

It can be written as a sum of positive squares in 4 ways, for example, as 34451814544 + 2096779296676 = 185612^2 + 1448026^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 2131231111192 and 2131231111201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 598658645 + ... + 598662204.

It is an arithmetic number, because the mean of its divisors is an integer number (188578033875).

Almost surely, 2^{2131231111220} is an apocalyptic number.

2131231111220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2131231111220 is an abundant number, since it is smaller than the sum of its proper divisors (2394641701780).

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

2131231111220 is a wasteful number, since it uses less digits than its factorization.

2131231111220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1197320947 (or 1197320945 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 2131231111220 its reverse (221111321312), we get a palindrome (2352342432532).

The spelling of 2131231111220 in words is "two trillion, one hundred thirty-one billion, two hundred thirty-one million, one hundred eleven thousand, two hundred twenty".