21320309999 has 8 divisors (see below), whose sum is σ = 21793943808. Its totient is φ = 20847510040.

The previous prime is 21320309981. The next prime is 21320310017. The reversal of 21320309999 is 99990302312.

It is an interprime number because it is at equal distance from previous prime (21320309981) and next prime (21320310017).

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

It is a cyclic number.

It is not a de Polignac number, because 21320309999 - 2³² = 17025342703 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320300999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156617 + ... + 259170.

It is an arithmetic number, because the mean of its divisors is an integer number (2724242976).

Almost surely, 2^21320309999 is an apocalyptic number.

21320309999 is a deficient number, since it is larger than the sum of its proper divisors (473633809).

21320309999 is a wasteful number, since it uses less digits than its factorization.

21320309999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 416925.

The product of its (nonzero) digits is 236196, while the sum is 47.

The spelling of 21320309999 in words is "twenty-one billion, three hundred twenty million, three hundred nine thousand, nine hundred ninety-nine".