21310121020 has 12 divisors (see below), whose sum is σ = 44751254184. Its totient is φ = 8524048400.

The previous prime is 21310121017. The next prime is 21310121071. The reversal of 21310121020 is 2012101312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 532753006 + ... + 532753045.

It is an arithmetic number, because the mean of its divisors is an integer number (3729271182).

Almost surely, 2^21310121020 is an apocalyptic number.

21310121020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21310121020 is an abundant number, since it is smaller than the sum of its proper divisors (23441133164).

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

21310121020 is a wasteful number, since it uses less digits than its factorization.

21310121020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1065506060 (or 1065506058 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21310121020 its reverse (2012101312), we get a palindrome (23322222332).

The spelling of 21310121020 in words is "twenty-one billion, three hundred ten million, one hundred twenty-one thousand, twenty".