31279109 has 2 divisors, whose sum is σ = 31279110. Its totient is φ = 31279108.

The previous prime is 31279067. The next prime is 31279159. The reversal of 31279109 is 90197213.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28922884 + 2356225 = 5378^2 + 1535^2 .

It is an emirp because it is prime and its reverse (90197213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31279109 - 2¹⁶ = 31213573 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31279159) 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, 15639554 + 15639555.

It is an arithmetic number, because the mean of its divisors is an integer number (15639555).

Almost surely, 2^31279109 is an apocalyptic number.

It is an amenable number.

31279109 is a deficient number, since it is larger than the sum of its proper divisors (1).

31279109 is an equidigital number, since it uses as much as digits as its factorization.

31279109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3402, while the sum is 32.

The square root of 31279109 is about 5592.7729258392. The cubic root of 31279109 is about 315.0780322345.

The spelling of 31279109 in words is "thirty-one million, two hundred seventy-nine thousand, one hundred nine".