27992721 has 8 divisors (see below), whose sum is σ = 38527744. Its totient is φ = 18059760.

The previous prime is 27992641. The next prime is 27992729. The reversal of 27992721 is 12729972.

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

It is not a de Polignac number, because 27992721 - 2⁷ = 27992593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 27992721.

It is not an unprimeable number, because it can be changed into a prime (27992729) 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 7 ways as a sum of consecutive naturals, for example, 150406 + ... + 150591.

It is an arithmetic number, because the mean of its divisors is an integer number (4815968).

Almost surely, 2^27992721 is an apocalyptic number.

It is an amenable number.

27992721 is a deficient number, since it is larger than the sum of its proper divisors (10535023).

27992721 is a wasteful number, since it uses less digits than its factorization.

27992721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301031.

The product of its digits is 31752, while the sum is 39.

The square root of 27992721 is about 5290.8147765727. The cubic root of 27992721 is about 303.6325814176.

The spelling of 27992721 in words is "twenty-seven million, nine hundred ninety-two thousand, seven hundred twenty-one".