27997961 has 2 divisors, whose sum is σ = 27997962. Its totient is φ = 27997960.

The previous prime is 27997943. The next prime is 27997973. The reversal of 27997961 is 16979972.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17272336 + 10725625 = 4156^2 + 3275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-27997961 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (27997901) 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, 13998980 + 13998981.

It is an arithmetic number, because the mean of its divisors is an integer number (13998981).

Almost surely, 2^27997961 is an apocalyptic number.

It is an amenable number.

27997961 is a deficient number, since it is larger than the sum of its proper divisors (1).

27997961 is an equidigital number, since it uses as much as digits as its factorization.

27997961 is an odious number, because the sum of its binary digits is odd.

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

The square root of 27997961 is about 5291.3099512314. The cubic root of 27997961 is about 303.6515260504.

The spelling of 27997961 in words is "twenty-seven million, nine hundred ninety-seven thousand, nine hundred sixty-one".