27978669 has 8 divisors (see below), whose sum is σ = 41449920. Its totient is φ = 18652428.

The previous prime is 27978661. The next prime is 27978701. The reversal of 27978669 is 96687972.

It is not a de Polignac number, because 27978669 - 2³ = 27978661 is a prime.

It is a super-2 number, since 2×27978669² = 1565611838023122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27978661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 518097 + ... + 518150.

It is an arithmetic number, because the mean of its divisors is an integer number (5181240).

Almost surely, 2^27978669 is an apocalyptic number.

It is an amenable number.

27978669 is a deficient number, since it is larger than the sum of its proper divisors (13471251).

27978669 is a wasteful number, since it uses less digits than its factorization.

27978669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1036256 (or 1036250 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The square root of 27978669 is about 5289.4866480595. The cubic root of 27978669 is about 303.5817663126.

The spelling of 27978669 in words is "twenty-seven million, nine hundred seventy-eight thousand, six hundred sixty-nine".