21002100021113 has 4 divisors (see below), whose sum is σ = 21002397685668. Its totient is φ = 21001802356560.

The previous prime is 21002100021103. The next prime is 21002100021143. The reversal of 21002100021113 is 31112000120012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13051803601984 + 7950296419129 = 3612728^2 + 2819627^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002100021113 - 2¹⁰ = 21002100020089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002100021103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148726418 + ... + 148867563.

It is an arithmetic number, because the mean of its divisors is an integer number (5250599421417).

Almost surely, 2^{21002100021113} is an apocalyptic number.

It is an amenable number.

21002100021113 is a deficient number, since it is larger than the sum of its proper divisors (297664555).

21002100021113 is an equidigital number, since it uses as much as digits as its factorization.

21002100021113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297664554.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21002100021113 its reverse (31112000120012), we get a palindrome (52114100141125).

The spelling of 21002100021113 in words is "twenty-one trillion, two billion, one hundred million, twenty-one thousand, one hundred thirteen".