21347691716 has 12 divisors (see below), whose sum is σ = 40232188332. Its totient is φ = 9852780768.

The previous prime is 21347691713. The next prime is 21347691731. The reversal of 21347691716 is 61719674312.

It can be written as a sum of positive squares in 2 ways, for example, as 1369000000 + 19978691716 = 37000^2 + 141346^2 .

It is not an unprimeable number, because it can be changed into a prime (21347691713) 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 3 ways as a sum of consecutive naturals, for example, 205266215 + ... + 205266318.

It is an arithmetic number, because the mean of its divisors is an integer number (3352682361).

Almost surely, 2^21347691716 is an apocalyptic number.

21347691716 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

21347691716 is a deficient number, since it is larger than the sum of its proper divisors (18884496616).

21347691716 is a wasteful number, since it uses less digits than its factorization.

21347691716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410532550 (or 410532548 counting only the distinct ones).

The product of its digits is 381024, while the sum is 47.

The spelling of 21347691716 in words is "twenty-one billion, three hundred forty-seven million, six hundred ninety-one thousand, seven hundred sixteen".