27920731 has 4 divisors (see below), whose sum is σ = 28065592. Its totient is φ = 27775872.

The previous prime is 27920719. The next prime is 27920779. The reversal of 27920731 is 13702972.

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

It is a cyclic number.

It is not a de Polignac number, because 27920731 - 2⁵ = 27920699 is a prime.

It is a super-2 number, since 2×27920731² = 1559134439148722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 27920693 and 27920702.

It is not an unprimeable number, because it can be changed into a prime (27920231) 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, 72141 + ... + 72526.

It is an arithmetic number, because the mean of its divisors is an integer number (7016398).

Almost surely, 2^27920731 is an apocalyptic number.

27920731 is a deficient number, since it is larger than the sum of its proper divisors (144861).

27920731 is a wasteful number, since it uses less digits than its factorization.

27920731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144860.

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 27920731 is about 5284.0070968915. The cubic root of 27920731 is about 303.3720699500.

The spelling of 27920731 in words is "twenty-seven million, nine hundred twenty thousand, seven hundred thirty-one".