21319597985 has 16 divisors (see below), whose sum is σ = 29674701696. Its totient is φ = 14400955008.

The previous prime is 21319597973. The next prime is 21319598009. The reversal of 21319597985 is 58979591312.

It is a cyclic number.

It is not a de Polignac number, because 21319597985 - 2²⁰ = 21318549409 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 4543412 + ... + 4548101.

It is an arithmetic number, because the mean of its divisors is an integer number (1854668856).

Almost surely, 2^21319597985 is an apocalyptic number.

It is an amenable number.

21319597985 is a deficient number, since it is larger than the sum of its proper divisors (8355103711).

21319597985 is an equidigital number, since it uses as much as digits as its factorization.

21319597985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9091592.

The product of its digits is 6123600, while the sum is 59.

The spelling of 21319597985 in words is "twenty-one billion, three hundred nineteen million, five hundred ninety-seven thousand, nine hundred eighty-five".