21020122002100 has 72 divisors (see below), whose sum is σ = 49131854309720. Its totient is φ = 7759783342080.

The previous prime is 21020122002079. The next prime is 21020122002101. The reversal of 21020122002100 is 120022102012.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 1285257550864 + 19734864451236 = 1133692^2 + 4442394^2 .

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21020122002101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5219644 + ... + 8323756.

Almost surely, 2^{21020122002100} is an apocalyptic number.

21020122002100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21020122002100 is an abundant number, since it is smaller than the sum of its proper divisors (28111732307620).

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

21020122002100 is a wasteful number, since it uses less digits than its factorization.

21020122002100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3109349 (or 3109342 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21020122002100 its reverse (120022102012), we get a palindrome (21140144104112).

The spelling of 21020122002100 in words is "twenty-one trillion, twenty billion, one hundred twenty-two million, two thousand, one hundred".