27985921 has 2 divisors, whose sum is σ = 27985922. Its totient is φ = 27985920.

The previous prime is 27985913. The next prime is 27985933. The reversal of 27985921 is 12958972.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17514225 + 10471696 = 4185^2 + 3236^2 .

It is a cyclic number.

It is not a de Polignac number, because 27985921 - 2³ = 27985913 is a prime.

It is not a weakly prime, because it can be changed into another prime (27985981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13992960 + 13992961.

It is an arithmetic number, because the mean of its divisors is an integer number (13992961).

Almost surely, 2^27985921 is an apocalyptic number.

It is an amenable number.

27985921 is a deficient number, since it is larger than the sum of its proper divisors (1).

27985921 is an equidigital number, since it uses as much as digits as its factorization.

27985921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 90720, while the sum is 43.

The square root of 27985921 is about 5290.1721144023. The cubic root of 27985921 is about 303.6079932546.

The spelling of 27985921 in words is "twenty-seven million, nine hundred eighty-five thousand, nine hundred twenty-one".