21704641704 has 24 divisors (see below), whose sum is σ = 58783404810. Its totient is φ = 7234880544.

The previous prime is 21704641703. The next prime is 21704641729. The reversal of 21704641704 is 40714640712.

It is a happy number.

21704641704 is a `hidden beast` number, since 2 + 1 + 7 + 0 + 4 + 641 + 7 + 0 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 21109184100 + 595457604 = 145290^2 + 24402^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21704641703) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 150726607 + ... + 150726750.

Almost surely, 2^21704641704 is an apocalyptic number.

21704641704 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21704641704 is an abundant number, since it is smaller than the sum of its proper divisors (37078763106).

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

21704641704 is a wasteful number, since it uses less digits than its factorization.

21704641704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301453369 (or 301453362 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The spelling of 21704641704 in words is "twenty-one billion, seven hundred four million, six hundred forty-one thousand, seven hundred four".