21627569 has 2 divisors, whose sum is σ = 21627570. Its totient is φ = 21627568.

The previous prime is 21627539. The next prime is 21627583. The reversal of 21627569 is 96572612.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21529600 + 97969 = 4640^2 + 313^2 .

It is a cyclic number.

It is not a de Polignac number, because 21627569 - 2⁸ = 21627313 is a prime.

It is a super-2 number, since 2×21627569² = 935503481699522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21627539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10813784 + 10813785.

It is an arithmetic number, because the mean of its divisors is an integer number (10813785).

Almost surely, 2^21627569 is an apocalyptic number.

It is an amenable number.

21627569 is a deficient number, since it is larger than the sum of its proper divisors (1).

21627569 is an equidigital number, since it uses as much as digits as its factorization.

21627569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 38.

The square root of 21627569 is about 4650.5450218227. The cubic root of 21627569 is about 278.6137647938.

The spelling of 21627569 in words is "twenty-one million, six hundred twenty-seven thousand, five hundred sixty-nine".