27731813 has 4 divisors (see below), whose sum is σ = 28937568. Its totient is φ = 26526060.

The previous prime is 27731807. The next prime is 27731827. The reversal of 27731813 is 31813772.

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 27731813 - 2⁴ = 27731797 is a prime.

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 27731813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27731113) 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, 602843 + ... + 602888.

It is an arithmetic number, because the mean of its divisors is an integer number (7234392).

Almost surely, 2^27731813 is an apocalyptic number.

27731813 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

27731813 is a deficient number, since it is larger than the sum of its proper divisors (1205755).

27731813 is a wasteful number, since it uses less digits than its factorization.

27731813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1205754.

The product of its digits is 7056, while the sum is 32.

The square root of 27731813 is about 5266.1003598488. The cubic root of 27731813 is about 302.6862928260.

The spelling of 27731813 in words is "twenty-seven million, seven hundred thirty-one thousand, eight hundred thirteen".