21566870701 has 8 divisors (see below), whose sum is σ = 22870068984. Its totient is φ = 20267512320.

The previous prime is 21566870693. The next prime is 21566870711. The reversal of 21566870701 is 10707866512.

It can be written as a sum of positive squares in 4 ways, for example, as 13449040900 + 8117829801 = 115970^2 + 90099^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21566870701 - 2³ = 21566870693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21566870711) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 948400 + ... + 970873.

It is an arithmetic number, because the mean of its divisors is an integer number (2858758623).

Almost surely, 2^21566870701 is an apocalyptic number.

It is an amenable number.

21566870701 is a deficient number, since it is larger than the sum of its proper divisors (1303198283).

21566870701 is a wasteful number, since it uses less digits than its factorization.

21566870701 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1919951.

The product of its (nonzero) digits is 141120, while the sum is 43.

The spelling of 21566870701 in words is "twenty-one billion, five hundred sixty-six million, eight hundred seventy thousand, seven hundred one".