21665700705 has 32 divisors (see below), whose sum is σ = 37939765248. Its totient is φ = 10470340800.

The previous prime is 21665700697. The next prime is 21665700709. The reversal of 21665700705 is 50700756612.

It is not a de Polignac number, because 21665700705 - 2³ = 21665700697 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21665700709) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 163201 + ... + 264510.

It is an arithmetic number, because the mean of its divisors is an integer number (1185617664).

Almost surely, 2^21665700705 is an apocalyptic number.

It is an amenable number.

21665700705 is a deficient number, since it is larger than the sum of its proper divisors (16274064543).

21665700705 is a wasteful number, since it uses less digits than its factorization.

21665700705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 428037.

The product of its (nonzero) digits is 88200, while the sum is 39.

The spelling of 21665700705 in words is "twenty-one billion, six hundred sixty-five million, seven hundred thousand, seven hundred five".