27331991 has 2 divisors, whose sum is σ = 27331992. Its totient is φ = 27331990.

The previous prime is 27331943. The next prime is 27331999. The reversal of 27331991 is 19913372.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27331991 - 2¹⁰ = 27330967 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27331999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13665995 + 13665996.

It is an arithmetic number, because the mean of its divisors is an integer number (13665996).

Almost surely, 2^27331991 is an apocalyptic number.

27331991 is a deficient number, since it is larger than the sum of its proper divisors (1).

27331991 is an equidigital number, since it uses as much as digits as its factorization.

27331991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10206, while the sum is 35.

The square root of 27331991 is about 5228.0006694720. Note that the first 3 decimals coincide. The cubic root of 27331991 is about 301.2245907530.

The spelling of 27331991 in words is "twenty-seven million, three hundred thirty-one thousand, nine hundred ninety-one".