21988627 has 2 divisors, whose sum is σ = 21988628. Its totient is φ = 21988626.

The previous prime is 21988601. The next prime is 21988649. The reversal of 21988627 is 72688912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21988627 - 2¹⁵ = 21955859 is a prime.

It is not a weakly prime, because it can be changed into another prime (21988657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10994313 + 10994314.

It is an arithmetic number, because the mean of its divisors is an integer number (10994314).

Almost surely, 2^21988627 is an apocalyptic number.

21988627 is a deficient number, since it is larger than the sum of its proper divisors (1).

21988627 is an equidigital number, since it uses as much as digits as its factorization.

21988627 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 43.

The square root of 21988627 is about 4689.2032372248. The cubic root of 21988627 is about 280.1556405106.

The spelling of 21988627 in words is "twenty-one million, nine hundred eighty-eight thousand, six hundred twenty-seven".