21641562023 has 4 divisors (see below), whose sum is σ = 21843819720. Its totient is φ = 21439304328.

The previous prime is 21641561989. The next prime is 21641562119. The reversal of 21641562023 is 32026514612.

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

It is a cyclic number.

It is not a de Polignac number, because 21641562023 - 2⁶ = 21641561959 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 (21641562223) 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, 101128688 + ... + 101128901.

It is an arithmetic number, because the mean of its divisors is an integer number (5460954930).

Almost surely, 2^21641562023 is an apocalyptic number.

21641562023 is a deficient number, since it is larger than the sum of its proper divisors (202257697).

21641562023 is a wasteful number, since it uses less digits than its factorization.

21641562023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202257696.

The product of its (nonzero) digits is 17280, while the sum is 32.

The spelling of 21641562023 in words is "twenty-one billion, six hundred forty-one million, five hundred sixty-two thousand, twenty-three".