21120021000100 has 54 divisors (see below), whose sum is σ = 50375613754802. Its totient is φ = 7680007632000.

The previous prime is 21120021000079. The next prime is 21120021000149. The reversal of 21120021000100 is 100012002112.

It can be written as a sum of positive squares in 3 ways, for example, as 2836341012736 + 18283679987364 = 1684144^2 + 4275942^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 872716041 + ... + 872740240.

Almost surely, 2^{21120021000100} is an apocalyptic number.

21120021000100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120021000100 is an abundant number, since it is smaller than the sum of its proper divisors (29255592754702).

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

21120021000100 is a wasteful number, since it uses less digits than its factorization.

21120021000100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1745456317 (or 1745456299 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 21120021000100 its reverse (100012002112), we get a palindrome (21220033002212).

The spelling of 21120021000100 in words is "twenty-one trillion, one hundred twenty billion, twenty-one million, one hundred", and thus it is an aban number.