21365769231 has 12 divisors (see below), whose sum is σ = 30928617720. Its totient is φ = 14212945680.

The previous prime is 21365769221. The next prime is 21365769233. The reversal of 21365769231 is 13296756312.

21365769231 is a `hidden beast` number, since 21 + 36 + 576 + 9 + 23 + 1 = 666.

It is not a de Polignac number, because 21365769231 - 2⁵ = 21365769199 is a prime.

It is a super-2 number, since 2×21365769231² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21365769233) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2570661 + ... + 2578958.

It is an arithmetic number, because the mean of its divisors is an integer number (2577384810).

Almost surely, 2^21365769231 is an apocalyptic number.

21365769231 is a deficient number, since it is larger than the sum of its proper divisors (9562848489).

21365769231 is a wasteful number, since it uses less digits than its factorization.

21365769231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5150086 (or 5150083 counting only the distinct ones).

The product of its digits is 408240, while the sum is 45.

The spelling of 21365769231 in words is "twenty-one billion, three hundred sixty-five million, seven hundred sixty-nine thousand, two hundred thirty-one".