21312102309 has 16 divisors (see below), whose sum is σ = 30105260352. Its totient is φ = 13364483328.

The previous prime is 21312102281. The next prime is 21312102337. The reversal of 21312102309 is 90320121312.

It is an interprime number because it is at equal distance from previous prime (21312102281) and next prime (21312102337).

It is not a de Polignac number, because 21312102309 - 2⁷ = 21312102181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21312102359) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33394 + ... + 209139.

It is an arithmetic number, because the mean of its divisors is an integer number (1881578772).

Almost surely, 2^21312102309 is an apocalyptic number.

It is an amenable number.

21312102309 is a deficient number, since it is larger than the sum of its proper divisors (8793158043).

21312102309 is a wasteful number, since it uses less digits than its factorization.

21312102309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 244276.

The product of its (nonzero) digits is 648, while the sum is 24.

The spelling of 21312102309 in words is "twenty-one billion, three hundred twelve million, one hundred two thousand, three hundred nine".