21677663 has 8 divisors (see below), whose sum is σ = 24842880. Its totient is φ = 18529560.

The previous prime is 21677653. The next prime is 21677681. The reversal of 21677663 is 36677612.

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

It is not a de Polignac number, because 21677663 - 2⁶ = 21677599 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 (21677653) 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, 1433 + ... + 6738.

It is an arithmetic number, because the mean of its divisors is an integer number (3105360).

Almost surely, 2^21677663 is an apocalyptic number.

21677663 is a deficient number, since it is larger than the sum of its proper divisors (3165217).

21677663 is an equidigital number, since it uses as much as digits as its factorization.

21677663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8557.

The product of its digits is 63504, while the sum is 38.

The square root of 21677663 is about 4655.9277271023. The cubic root of 21677663 is about 278.8287082931.

The spelling of 21677663 in words is "twenty-one million, six hundred seventy-seven thousand, six hundred sixty-three".