21701920659 has 8 divisors (see below), whose sum is σ = 28943400192. Its totient is φ = 14464194120.

The previous prime is 21701920657. The next prime is 21701920693. The reversal of 21701920659 is 95602910712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21701920659 - 2¹ = 21701920657 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21701920659.

It is not an unprimeable number, because it can be changed into a prime (21701920657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 924727 + ... + 947904.

It is an arithmetic number, because the mean of its divisors is an integer number (3617925024).

Almost surely, 2^21701920659 is an apocalyptic number.

21701920659 is a deficient number, since it is larger than the sum of its proper divisors (7241479533).

21701920659 is a wasteful number, since it uses less digits than its factorization.

21701920659 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1876497.

The product of its (nonzero) digits is 68040, while the sum is 42.

The spelling of 21701920659 in words is "twenty-one billion, seven hundred one million, nine hundred twenty thousand, six hundred fifty-nine".