231132121220 has 288 divisors, whose sum is σ = 667799596800. Its totient is φ = 65368765440.

The previous prime is 231132121211. The next prime is 231132121243. The reversal of 231132121220 is 22121231132.

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 = 231132121192 and 231132121201.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12984086 + ... + 13001874.

It is an arithmetic number, because the mean of its divisors is an integer number (2318748600).

Almost surely, 2^231132121220 is an apocalyptic number.

231132121220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 231132121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (333899798400).

231132121220 is an abundant number, since it is smaller than the sum of its proper divisors (436667475580).

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

231132121220 is a wasteful number, since it uses less digits than its factorization.

231132121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17899 (or 17886 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 231132121220 its reverse (22121231132), we get a palindrome (253253352352).

The spelling of 231132121220 in words is "two hundred thirty-one billion, one hundred thirty-two million, one hundred twenty-one thousand, two hundred twenty".