21317836608 has 70 divisors (see below), whose sum is σ = 63192761346. Its totient is φ = 7105943808.

The previous prime is 21317836583. The next prime is 21317836633. The reversal of 21317836608 is 80663871312.

21317836608 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 7 + 8 + 36 + 608 = 666.

It is an interprime number because it is at equal distance from previous prime (21317836583) and next prime (21317836633).

It can be written as a sum of positive squares in only one way, i.e., 18733944384 + 2583892224 = 136872^2 + 50832^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 2050935 + ... + 2061302.

Almost surely, 2^21317836608 is an apocalyptic number.

It is an amenable number.

21317836608 is an abundant number, since it is smaller than the sum of its proper divisors (41874924738).

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

21317836608 is an equidigital number, since it uses as much as digits as its factorization.

21317836608 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4112261 (or 4112242 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The spelling of 21317836608 in words is "twenty-one billion, three hundred seventeen million, eight hundred thirty-six thousand, six hundred eight".