27657991 has 2 divisors, whose sum is σ = 27657992. Its totient is φ = 27657990.

The previous prime is 27657953. The next prime is 27658027. The reversal of 27657991 is 19975672.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 27657991 - 2²¹ = 25560839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (27657911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13828995 + 13828996.

It is an arithmetic number, because the mean of its divisors is an integer number (13828996).

Almost surely, 2^27657991 is an apocalyptic number.

27657991 is a deficient number, since it is larger than the sum of its proper divisors (1).

27657991 is an equidigital number, since it uses as much as digits as its factorization.

27657991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 238140, while the sum is 46.

The square root of 27657991 is about 5259.0865176378. The cubic root of 27657991 is about 302.4174708268.

The spelling of 27657991 in words is "twenty-seven million, six hundred fifty-seven thousand, nine hundred ninety-one".