21431424312623 has 4 divisors (see below), whose sum is σ = 23079995413608. Its totient is φ = 19782853211640.

The previous prime is 21431424312607. The next prime is 21431424312637. The reversal of 21431424312623 is 32621342413412.

It is a happy number.

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 21431424312623 - 2⁴ = 21431424312607 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 (21431424312653) 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, 824285550473 + ... + 824285550498.

It is an arithmetic number, because the mean of its divisors is an integer number (5769998853402).

Almost surely, 2^{21431424312623} is an apocalyptic number.

21431424312623 is a deficient number, since it is larger than the sum of its proper divisors (1648571100985).

21431424312623 is a wasteful number, since it uses less digits than its factorization.

21431424312623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648571100984.

The product of its digits is 165888, while the sum is 38.

The spelling of 21431424312623 in words is "twenty-one trillion, four hundred thirty-one billion, four hundred twenty-four million, three hundred twelve thousand, six hundred twenty-three".