21113012023 has 4 divisors (see below), whose sum is σ = 21322051848. Its totient is φ = 20903972200.

The previous prime is 21113012009. The next prime is 21113012027. The reversal of 21113012023 is 32021031112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21113012023 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21113011988 and 21113012006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21113012027) 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, 104519761 + ... + 104519962.

It is an arithmetic number, because the mean of its divisors is an integer number (5330512962).

Almost surely, 2^21113012023 is an apocalyptic number.

21113012023 is a deficient number, since it is larger than the sum of its proper divisors (209039825).

21113012023 is a wasteful number, since it uses less digits than its factorization.

21113012023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209039824.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21113012023 its reverse (32021031112), we get a palindrome (53134043135).

The spelling of 21113012023 in words is "twenty-one billion, one hundred thirteen million, twelve thousand, twenty-three".