21409312499 has 12 divisors (see below), whose sum is σ = 22745008440. Its totient is φ = 20096216640.

The previous prime is 21409312493. The next prime is 21409312511. The reversal of 21409312499 is 99421390412.

It is not a de Polignac number, because 21409312499 - 2²⁰ = 21408263923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21409312493) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 178319 + ... + 273159.

It is an arithmetic number, because the mean of its divisors is an integer number (1895417370).

Almost surely, 2^21409312499 is an apocalyptic number.

21409312499 is a deficient number, since it is larger than the sum of its proper divisors (1335695941).

21409312499 is an equidigital number, since it uses as much as digits as its factorization.

21409312499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95078 (or 94969 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 44.

The spelling of 21409312499 in words is "twenty-one billion, four hundred nine million, three hundred twelve thousand, four hundred ninety-nine".