31406909 has 2 divisors, whose sum is σ = 31406910. Its totient is φ = 31406908.

The previous prime is 31406897. The next prime is 31406917. The reversal of 31406909 is 90960413.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18062500 + 13344409 = 4250^2 + 3653^2 .

It is an emirp because it is prime and its reverse (90960413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31406909 - 2⁸ = 31406653 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31406959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15703454 + 15703455.

It is an arithmetic number, because the mean of its divisors is an integer number (15703455).

Almost surely, 2^31406909 is an apocalyptic number.

It is an amenable number.

31406909 is a deficient number, since it is larger than the sum of its proper divisors (1).

31406909 is an equidigital number, since it uses as much as digits as its factorization.

31406909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 31406909 is about 5604.1867385018. The cubic root of 31406909 is about 315.5065637911.

The spelling of 31406909 in words is "thirty-one million, four hundred six thousand, nine hundred nine".