21662663 has 8 divisors (see below), whose sum is σ = 23792400. Its totient is φ = 19559680.

The previous prime is 21662653. The next prime is 21662671. The reversal of 21662663 is 36626612.

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 21662663 - 2¹⁰ = 21661639 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 (21662633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4970 + ... + 8247.

It is an arithmetic number, because the mean of its divisors is an integer number (2974050).

Almost surely, 2^21662663 is an apocalyptic number.

21662663 is a deficient number, since it is larger than the sum of its proper divisors (2129737).

21662663 is a wasteful number, since it uses less digits than its factorization.

21662663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13377.

The product of its digits is 15552, while the sum is 32.

The square root of 21662663 is about 4654.3165985996. The cubic root of 21662663 is about 278.7643810071.

The spelling of 21662663 in words is "twenty-one million, six hundred sixty-two thousand, six hundred sixty-three".