21675977 has 4 divisors (see below), whose sum is σ = 22137216. Its totient is φ = 21214740.

The previous prime is 21675949. The next prime is 21676007. The reversal of 21675977 is 77957612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21675977 - 2⁸ = 21675721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21675917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 230549 + ... + 230642.

It is an arithmetic number, because the mean of its divisors is an integer number (5534304).

Almost surely, 2^21675977 is an apocalyptic number.

It is an amenable number.

21675977 is a deficient number, since it is larger than the sum of its proper divisors (461239).

21675977 is an equidigital number, since it uses as much as digits as its factorization.

21675977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 461238.

The product of its digits is 185220, while the sum is 44.

The square root of 21675977 is about 4655.7466640701. The cubic root of 21675977 is about 278.8214793867.

The spelling of 21675977 in words is "twenty-one million, six hundred seventy-five thousand, nine hundred seventy-seven".