27661979 has 2 divisors, whose sum is σ = 27661980. Its totient is φ = 27661978.

The previous prime is 27661913. The next prime is 27662017. The reversal of 27661979 is 97916672.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27661979 - 2⁸ = 27661723 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (27661279) 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, 13830989 + 13830990.

It is an arithmetic number, because the mean of its divisors is an integer number (13830990).

Almost surely, 2^27661979 is an apocalyptic number.

27661979 is a deficient number, since it is larger than the sum of its proper divisors (1).

27661979 is an equidigital number, since it uses as much as digits as its factorization.

27661979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 47.

The square root of 27661979 is about 5259.4656572698. The cubic root of 27661979 is about 302.4320052990.

The spelling of 27661979 in words is "twenty-seven million, six hundred sixty-one thousand, nine hundred seventy-nine".