27880813 has 4 divisors (see below), whose sum is σ = 28529248. Its totient is φ = 27232380.

The previous prime is 27880793. The next prime is 27880841. The reversal of 27880813 is 31808872.

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 a de Polignac number, because none of the positive numbers 2^k-27880813 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 (27881813) 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, 324153 + ... + 324238.

It is an arithmetic number, because the mean of its divisors is an integer number (7132312).

Almost surely, 2^27880813 is an apocalyptic number.

It is an amenable number.

27880813 is a deficient number, since it is larger than the sum of its proper divisors (648435).

27880813 is an equidigital number, since it uses as much as digits as its factorization.

27880813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 648434.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 27880813 is about 5280.2284988436. The cubic root of 27880813 is about 303.2274249541.

The spelling of 27880813 in words is "twenty-seven million, eight hundred eighty thousand, eight hundred thirteen".