21766705 has 8 divisors (see below), whose sum is σ = 26308800. Its totient is φ = 17287536.

The previous prime is 21766651. The next prime is 21766709. The reversal of 21766705 is 50766712.

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 21766705 - 2²¹ = 19669553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21766709) 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, 14965 + ... + 16354.

It is an arithmetic number, because the mean of its divisors is an integer number (3288600).

Almost surely, 2^21766705 is an apocalyptic number.

It is an amenable number.

21766705 is a deficient number, since it is larger than the sum of its proper divisors (4542095).

21766705 is a wasteful number, since it uses less digits than its factorization.

21766705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31463.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 21766705 is about 4665.4801467802. The cubic root of 21766705 is about 279.2099540311.

The spelling of 21766705 in words is "twenty-one million, seven hundred sixty-six thousand, seven hundred five".