31313081 has 2 divisors, whose sum is σ = 31313082. Its totient is φ = 31313080.

The previous prime is 31313077. The next prime is 31313119. The reversal of 31313081 is 18031313.

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., 28987456 + 2325625 = 5384^2 + 1525^2 .

It is a cyclic number.

It is not a de Polignac number, because 31313081 - 2² = 31313077 is a prime.

It is a super-2 number, since 2×31313081² = 1961018083425122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31313041) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15656540 + 15656541.

It is an arithmetic number, because the mean of its divisors is an integer number (15656541).

Almost surely, 2^31313081 is an apocalyptic number.

It is an amenable number.

31313081 is a deficient number, since it is larger than the sum of its proper divisors (1).

31313081 is an equidigital number, since it uses as much as digits as its factorization.

31313081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 31313081 is about 5595.8092354904. The cubic root of 31313081 is about 315.1920589067.

Adding to 31313081 its reverse (18031313), we get a palindrome (49344394).

The spelling of 31313081 in words is "thirty-one million, three hundred thirteen thousand, eighty-one".