27979961 has 2 divisors, whose sum is σ = 27979962. Its totient is φ = 27979960.

The previous prime is 27979957. The next prime is 27979981. The reversal of 27979961 is 16997972.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23464336 + 4515625 = 4844^2 + 2125^2 .

It is a cyclic number.

It is not a de Polignac number, because 27979961 - 2² = 27979957 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27979901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13989980 + 13989981.

It is an arithmetic number, because the mean of its divisors is an integer number (13989981).

Almost surely, 2^27979961 is an apocalyptic number.

It is an amenable number.

27979961 is a deficient number, since it is larger than the sum of its proper divisors (1).

27979961 is an equidigital number, since it uses as much as digits as its factorization.

27979961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 428652, while the sum is 50.

The square root of 27979961 is about 5289.6087757035. The cubic root of 27979961 is about 303.5864391774.

The spelling of 27979961 in words is "twenty-seven million, nine hundred seventy-nine thousand, nine hundred sixty-one".