21002121030 has 64 divisors (see below), whose sum is σ = 56883513600. Its totient is φ = 4915854720.

The previous prime is 21002121013. The next prime is 21002121043. The reversal of 21002121030 is 3012120012.

It is a junction number, because it is equal to n+sod(n) for n = 21002120997 and 21002121015.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1087720 + ... + 1106859.

It is an arithmetic number, because the mean of its divisors is an integer number (888804900).

Almost surely, 2^21002121030 is an apocalyptic number.

21002121030 is an abundant number, since it is smaller than the sum of its proper divisors (35881392570).

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

21002121030 is a wasteful number, since it uses less digits than its factorization.

21002121030 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2194629.

The product of its (nonzero) digits is 24, while the sum is 12.

Adding to 21002121030 its reverse (3012120012), we get a palindrome (24014241042).

The spelling of 21002121030 in words is "twenty-one billion, two million, one hundred twenty-one thousand, thirty".