31099009 has 2 divisors, whose sum is σ = 31099010. Its totient is φ = 31099008.

The previous prime is 31098989. The next prime is 31099027. The reversal of 31099009 is 90099013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30558784 + 540225 = 5528^2 + 735^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31099009 is a prime.

It is not a weakly prime, because it can be changed into another prime (31099309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15549504 + 15549505.

It is an arithmetic number, because the mean of its divisors is an integer number (15549505).

Almost surely, 2^31099009 is an apocalyptic number.

It is an amenable number.

31099009 is a deficient number, since it is larger than the sum of its proper divisors (1).

31099009 is an equidigital number, since it uses as much as digits as its factorization.

31099009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2187, while the sum is 31.

The square root of 31099009 is about 5576.6485454976. The cubic root of 31099009 is about 314.4721452629.

The spelling of 31099009 in words is "thirty-one million, ninety-nine thousand, nine".