21727669 has 2 divisors, whose sum is σ = 21727670. Its totient is φ = 21727668.

The previous prime is 21727661. The next prime is 21727681. The reversal of 21727669 is 96672712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20593444 + 1134225 = 4538^2 + 1065^2 .

It is a cyclic number.

It is not a de Polignac number, because 21727669 - 2³ = 21727661 is a prime.

It is a super-2 number, since 2×21727669² = 944183200347122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21727661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10863834 + 10863835.

It is an arithmetic number, because the mean of its divisors is an integer number (10863835).

Almost surely, 2^21727669 is an apocalyptic number.

It is an amenable number.

21727669 is a deficient number, since it is larger than the sum of its proper divisors (1).

21727669 is an equidigital number, since it uses as much as digits as its factorization.

21727669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 63504, while the sum is 40.

The square root of 21727669 is about 4661.2947772051. The cubic root of 21727669 is about 279.0429441910.

The spelling of 21727669 in words is "twenty-one million, seven hundred twenty-seven thousand, six hundred sixty-nine".