231021121020 has 24 divisors (see below), whose sum is σ = 646859139024. Its totient is φ = 61605632256.

The previous prime is 231021121013. The next prime is 231021121021. The reversal of 231021121020 is 20121120132.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231021121021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1925175949 + ... + 1925176068.

It is an arithmetic number, because the mean of its divisors is an integer number (26952464126).

Almost surely, 2^231021121020 is an apocalyptic number.

231021121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231021121020 is an abundant number, since it is smaller than the sum of its proper divisors (415838018004).

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

231021121020 is a wasteful number, since it uses less digits than its factorization.

231021121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3850352029 (or 3850352027 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 231021121020 its reverse (20121120132), we get a palindrome (251142241152).

The spelling of 231021121020 in words is "two hundred thirty-one billion, twenty-one million, one hundred twenty-one thousand, twenty".