21676427 has 4 divisors (see below), whose sum is σ = 22423920. Its totient is φ = 20928936.

The previous prime is 21676387. The next prime is 21676469. The reversal of 21676427 is 72467612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21676427 - 2²⁴ = 4899211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21676927) 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 3 ways as a sum of consecutive naturals, for example, 373703 + ... + 373760.

It is an arithmetic number, because the mean of its divisors is an integer number (5605980).

Almost surely, 2^21676427 is an apocalyptic number.

21676427 is a deficient number, since it is larger than the sum of its proper divisors (747493).

21676427 is an equidigital number, since it uses as much as digits as its factorization.

21676427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747492.

The product of its digits is 28224, while the sum is 35.

The square root of 21676427 is about 4655.7949911911. The cubic root of 21676427 is about 278.8234088468.

The spelling of 21676427 in words is "twenty-one million, six hundred seventy-six thousand, four hundred twenty-seven".