27799861 has 4 divisors (see below), whose sum is σ = 28000000. Its totient is φ = 27599724.

The previous prime is 27799843. The next prime is 27799867. The reversal of 27799861 is 16899772.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 27799861 - 2⁵ = 27799829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27799867) 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 in 3 ways as a sum of consecutive naturals, for example, 99861 + ... + 100138.

It is an arithmetic number, because the mean of its divisors is an integer number (7000000).

Almost surely, 2^27799861 is an apocalyptic number.

It is an amenable number.

27799861 is a deficient number, since it is larger than the sum of its proper divisors (200139).

27799861 is a wasteful number, since it uses less digits than its factorization.

27799861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200138.

The product of its digits is 381024, while the sum is 49.

The square root of 27799861 is about 5272.5573491428. The cubic root of 27799861 is about 302.9336666361.

The spelling of 27799861 in words is "twenty-seven million, seven hundred ninety-nine thousand, eight hundred sixty-one".