27991982 has 4 divisors (see below), whose sum is σ = 41987976. Its totient is φ = 13995990.

The previous prime is 27991981. The next prime is 27991987. The reversal of 27991982 is 28919972.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (27991981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6997994 + ... + 6997997.

It is an arithmetic number, because the mean of its divisors is an integer number (10496994).

Almost surely, 2^27991982 is an apocalyptic number.

27991982 is a deficient number, since it is larger than the sum of its proper divisors (13995994).

27991982 is a wasteful number, since it uses less digits than its factorization.

27991982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13995993.

The product of its digits is 163296, while the sum is 47.

The square root of 27991982 is about 5290.7449380971. The cubic root of 27991982 is about 303.6299094557.

The spelling of 27991982 in words is "twenty-seven million, nine hundred ninety-one thousand, nine hundred eighty-two".