21224431075 has 6 divisors (see below), whose sum is σ = 26318294564. Its totient is φ = 16979544840.

The previous prime is 21224431069. The next prime is 21224431097. The reversal of 21224431075 is 57013442212.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-21224431075 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 424488597 + ... + 424488646.

Almost surely, 2^21224431075 is an apocalyptic number.

21224431075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21224431075 is a deficient number, since it is larger than the sum of its proper divisors (5093863489).

21224431075 is an equidigital number, since it uses as much as digits as its factorization.

21224431075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848977253 (or 848977248 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 31.

Adding to 21224431075 its reverse (57013442212), we get a palindrome (78237873287).

The spelling of 21224431075 in words is "twenty-one billion, two hundred twenty-four million, four hundred thirty-one thousand, seventy-five".