27591997 has 4 divisors (see below), whose sum is σ = 27679356. Its totient is φ = 27504640.

The previous prime is 27591989. The next prime is 27592027. The reversal of 27591997 is 79919572.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16695396 + 10896601 = 4086^2 + 3301^2 .

It is a cyclic number.

It is not a de Polignac number, because 27591997 - 2³ = 27591989 is a prime.

It is a super-2 number, since 2×27591997² = 1522636596896018, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 27591997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27591797) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43204 + ... + 43837.

It is an arithmetic number, because the mean of its divisors is an integer number (6919839).

Almost surely, 2^27591997 is an apocalyptic number.

It is an amenable number.

27591997 is a deficient number, since it is larger than the sum of its proper divisors (87359).

27591997 is an equidigital number, since it uses as much as digits as its factorization.

27591997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87358.

The product of its digits is 357210, while the sum is 49.

The square root of 27591997 is about 5252.8084868954. The cubic root of 27591997 is about 302.1767491587.

The spelling of 27591997 in words is "twenty-seven million, five hundred ninety-one thousand, nine hundred ninety-seven".