21627427 has 4 divisors (see below), whose sum is σ = 21783160. Its totient is φ = 21471696.

The previous prime is 21627421. The next prime is 21627449. The reversal of 21627427 is 72472612.

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 21627427 - 2⁷ = 21627299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21627421) 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, 77658 + ... + 77935.

It is an arithmetic number, because the mean of its divisors is an integer number (5445790).

Almost surely, 2^21627427 is an apocalyptic number.

21627427 is a deficient number, since it is larger than the sum of its proper divisors (155733).

21627427 is a wasteful number, since it uses less digits than its factorization.

21627427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155732.

The product of its digits is 9408, while the sum is 31.

The square root of 21627427 is about 4650.5297547699. The cubic root of 21627427 is about 278.6131550282.

The spelling of 21627427 in words is "twenty-one million, six hundred twenty-seven thousand, four hundred twenty-seven".