21766406663 has 16 divisors (see below), whose sum is σ = 22786920000. Its totient is φ = 20764246272.

The previous prime is 21766406659. The next prime is 21766406693. The reversal of 21766406663 is 36660466712.

It is a cyclic number.

It is not a de Polignac number, because 21766406663 - 2² = 21766406659 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 (21766406633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5028206 + ... + 5032532.

It is an arithmetic number, because the mean of its divisors is an integer number (1424182500).

Almost surely, 2^21766406663 is an apocalyptic number.

21766406663 is a deficient number, since it is larger than the sum of its proper divisors (1020513337).

21766406663 is a wasteful number, since it uses less digits than its factorization.

21766406663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6394.

The product of its (nonzero) digits is 1306368, while the sum is 47.

The spelling of 21766406663 in words is "twenty-one billion, seven hundred sixty-six million, four hundred six thousand, six hundred sixty-three".