27664702421 has 2 divisors, whose sum is σ = 27664702422. Its totient is φ = 27664702420.

The previous prime is 27664702409. The next prime is 27664702423. The reversal of 27664702421 is 12420746672.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21694049521 + 5970652900 = 147289^2 + 77270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27664702421 is a prime.

It is a super-2 number, since 2×27664702421² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

Together with 27664702423, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27664702423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13832351210 + 13832351211.

It is an arithmetic number, because the mean of its divisors is an integer number (13832351211).

Almost surely, 2^27664702421 is an apocalyptic number.

It is an amenable number.

27664702421 is a deficient number, since it is larger than the sum of its proper divisors (1).

27664702421 is an equidigital number, since it uses as much as digits as its factorization.

27664702421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 225792, while the sum is 41.

The spelling of 27664702421 in words is "twenty-seven billion, six hundred sixty-four million, seven hundred two thousand, four hundred twenty-one".