31278089 has 2 divisors, whose sum is σ = 31278090. Its totient is φ = 31278088.

The previous prime is 31278053. The next prime is 31278097. The reversal of 31278089 is 98087213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30030400 + 1247689 = 5480^2 + 1117^2 .

It is a cyclic number.

It is not a de Polignac number, because 31278089 - 2⁸ = 31277833 is a prime.

It is not a weakly prime, because it can be changed into another prime (31278019) 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 as a sum of consecutive naturals, namely, 15639044 + 15639045.

It is an arithmetic number, because the mean of its divisors is an integer number (15639045).

Almost surely, 2^31278089 is an apocalyptic number.

It is an amenable number.

31278089 is a deficient number, since it is larger than the sum of its proper divisors (1).

31278089 is an equidigital number, since it uses as much as digits as its factorization.

31278089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 31278089 is about 5592.6817359832. The cubic root of 31278089 is about 315.0746073385.

The spelling of 31278089 in words is "thirty-one million, two hundred seventy-eight thousand, eighty-nine".