21102120023 has 4 divisors (see below), whose sum is σ = 21102410880. Its totient is φ = 21101829168.

The previous prime is 21102119993. The next prime is 21102120041. The reversal of 21102120023 is 32002120112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21102120023 - 2¹⁴ = 21102103639 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 (21102120073) 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, 62411 + ... + 214707.

It is an arithmetic number, because the mean of its divisors is an integer number (5275602720).

Almost surely, 2^21102120023 is an apocalyptic number.

21102120023 is a deficient number, since it is larger than the sum of its proper divisors (290857).

21102120023 is a wasteful number, since it uses less digits than its factorization.

21102120023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290856.

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21102120023 its reverse (32002120112), we get a palindrome (53104240135).

The spelling of 21102120023 in words is "twenty-one billion, one hundred two million, one hundred twenty thousand, twenty-three".