21465753231 has 8 divisors (see below), whose sum is σ = 30822620080. Its totient is φ = 13209694272.

The previous prime is 21465753229. The next prime is 21465753247. The reversal of 21465753231 is 13235756412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21465753231 - 2¹ = 21465753229 is a prime.

It is a super-2 number, since 2×21465753231² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 550403929 = 21465753231 / (2 + 1 + 4 + 6 + 5 + 7 + 5 + 3 + 2 + 3 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21465753231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21465753431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275201926 + ... + 275202003.

It is an arithmetic number, because the mean of its divisors is an integer number (3852827510).

Almost surely, 2^21465753231 is an apocalyptic number.

21465753231 is a deficient number, since it is larger than the sum of its proper divisors (9356866849).

21465753231 is a wasteful number, since it uses less digits than its factorization.

21465753231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550403945.

The product of its digits is 151200, while the sum is 39.

The spelling of 21465753231 in words is "twenty-one billion, four hundred sixty-five million, seven hundred fifty-three thousand, two hundred thirty-one".