31138249 has 2 divisors, whose sum is σ = 31138250. Its totient is φ = 31138248.

The previous prime is 31138213. The next prime is 31138259. The reversal of 31138249 is 94283113.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31136400 + 1849 = 5580^2 + 43^2 .

It is a cyclic number.

It is not a de Polignac number, because 31138249 - 2¹¹ = 31136201 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31138249.

It is not a weakly prime, because it can be changed into another prime (31138259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15569124 + 15569125.

It is an arithmetic number, because the mean of its divisors is an integer number (15569125).

Almost surely, 2^31138249 is an apocalyptic number.

It is an amenable number.

31138249 is a deficient number, since it is larger than the sum of its proper divisors (1).

31138249 is an equidigital number, since it uses as much as digits as its factorization.

31138249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5184, while the sum is 31.

The square root of 31138249 is about 5580.1656785440. The cubic root of 31138249 is about 314.6043541977.

The spelling of 31138249 in words is "thirty-one million, one hundred thirty-eight thousand, two hundred forty-nine".