21100223210021 has 16 divisors (see below), whose sum is σ = 21585055322880. Its totient is φ = 20618655071040.

The previous prime is 21100223209963. The next prime is 21100223210023. The reversal of 21100223210021 is 12001232200112.

It is a cyclic number.

It is not a de Polignac number, because 21100223210021 - 2¹⁸ = 21100222947877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100223210023) 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, 41962931 + ... + 42462783.

It is an arithmetic number, because the mean of its divisors is an integer number (1349065957680).

Almost surely, 2^{21100223210021} is an apocalyptic number.

It is an amenable number.

21100223210021 is a deficient number, since it is larger than the sum of its proper divisors (484832112859).

21100223210021 is a wasteful number, since it uses less digits than its factorization.

21100223210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503116.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21100223210021 its reverse (12001232200112), we get a palindrome (33101455410133).

The spelling of 21100223210021 in words is "twenty-one trillion, one hundred billion, two hundred twenty-three million, two hundred ten thousand, twenty-one".