21265731423 has 24 divisors (see below), whose sum is σ = 30799828800. Its totient is φ = 14139062784.

The previous prime is 21265731413. The next prime is 21265731433. The reversal of 21265731423 is 32413756212.

21265731423 is a `hidden beast` number, since 21 + 26 + 573 + 1 + 42 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (21265731413) and next prime (21265731433).

It is not a de Polignac number, because 21265731423 - 2⁶ = 21265731359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21265731413) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6527611 + ... + 6530867.

It is an arithmetic number, because the mean of its divisors is an integer number (1283326200).

Almost surely, 2^21265731423 is an apocalyptic number.

21265731423 is a deficient number, since it is larger than the sum of its proper divisors (9534097377).

21265731423 is a wasteful number, since it uses less digits than its factorization.

21265731423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4991 (or 4988 counting only the distinct ones).

The product of its digits is 60480, while the sum is 36.

The spelling of 21265731423 in words is "twenty-one billion, two hundred sixty-five million, seven hundred thirty-one thousand, four hundred twenty-three".