31475909 has 2 divisors, whose sum is σ = 31475910. Its totient is φ = 31475908.

The previous prime is 31475849. The next prime is 31475911. The reversal of 31475909 is 90957413.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 29920900 + 1555009 = 5470^2 + 1247^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31475909 is a prime.

Together with 31475911, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31475929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15737954 + 15737955.

It is an arithmetic number, because the mean of its divisors is an integer number (15737955).

Almost surely, 2^31475909 is an apocalyptic number.

It is an amenable number.

31475909 is a deficient number, since it is larger than the sum of its proper divisors (1).

31475909 is an equidigital number, since it uses as much as digits as its factorization.

31475909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 31475909 is about 5610.3394727949. The cubic root of 31475909 is about 315.7374474872.

The spelling of 31475909 in words is "thirty-one million, four hundred seventy-five thousand, nine hundred nine".