21308814708 has 24 divisors (see below), whose sum is σ = 50933265600. Its totient is φ = 6929695680.

The previous prime is 21308814643. The next prime is 21308814727. The reversal of 21308814708 is 80741880312.

It is a self number, because there is not a number n which added to its sum of digits gives 21308814708.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 21654808 + ... + 21655791.

It is an arithmetic number, because the mean of its divisors is an integer number (2122219400).

Almost surely, 2^21308814708 is an apocalyptic number.

It is an amenable number.

21308814708 is an abundant number, since it is smaller than the sum of its proper divisors (29624450892).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21308814708 is a wasteful number, since it uses less digits than its factorization.

21308814708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43310647 (or 43310645 counting only the distinct ones).

The product of its (nonzero) digits is 86016, while the sum is 42.

The spelling of 21308814708 in words is "twenty-one billion, three hundred eight million, eight hundred fourteen thousand, seven hundred eight".