27991403 has 8 divisors (see below), whose sum is σ = 30757440. Its totient is φ = 25262280.

The previous prime is 27991399. The next prime is 27991477. The reversal of 27991403 is 30419972.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 27991403 - 2² = 27991399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (27991493) 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, 7625 + ... + 10682.

It is an arithmetic number, because the mean of its divisors is an integer number (3844680).

Almost surely, 2^27991403 is an apocalyptic number.

27991403 is a deficient number, since it is larger than the sum of its proper divisors (2766037).

27991403 is a wasteful number, since it uses less digits than its factorization.

27991403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18457.

The product of its (nonzero) digits is 13608, while the sum is 35.

The square root of 27991403 is about 5290.6902196216. The cubic root of 27991403 is about 303.6278159642.

The spelling of 27991403 in words is "twenty-seven million, nine hundred ninety-one thousand, four hundred three".