21005627 has 2 divisors, whose sum is σ = 21005628. Its totient is φ = 21005626.

The previous prime is 21005623. The next prime is 21005651. The reversal of 21005627 is 72650012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21005627 - 2² = 21005623 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21005623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10502813 + 10502814.

It is an arithmetic number, because the mean of its divisors is an integer number (10502814).

Almost surely, 2^21005627 is an apocalyptic number.

21005627 is a deficient number, since it is larger than the sum of its proper divisors (1).

21005627 is an equidigital number, since it uses as much as digits as its factorization.

21005627 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 23.

The square root of 21005627 is about 4583.1896098678. The cubic root of 21005627 is about 275.9170574475.

Adding to 21005627 its reverse (72650012), we get a palindrome (93655639).

The spelling of 21005627 in words is "twenty-one million, five thousand, six hundred twenty-seven".