21112020100021 has 16 divisors (see below), whose sum is σ = 21404865729600. Its totient is φ = 20820463312000.

The previous prime is 21112020099991. The next prime is 21112020100057. The reversal of 21112020100021 is 12000102021112.

It is a cyclic number.

It is not a de Polignac number, because 21112020100021 - 2⁹ = 21112020099509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21112020099974 and 21112020100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112020100421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71019546 + ... + 71316196.

It is an arithmetic number, because the mean of its divisors is an integer number (1337804108100).

Almost surely, 2^{21112020100021} is an apocalyptic number.

It is an amenable number.

21112020100021 is a deficient number, since it is larger than the sum of its proper divisors (292845629579).

21112020100021 is a wasteful number, since it uses less digits than its factorization.

21112020100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298820.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21112020100021 its reverse (12000102021112), we get a palindrome (33112122121133).

The spelling of 21112020100021 in words is "twenty-one trillion, one hundred twelve billion, twenty million, one hundred thousand, twenty-one".