31007213 has 2 divisors, whose sum is σ = 31007214. Its totient is φ = 31007212.

The previous prime is 31007159. The next prime is 31007219. The reversal of 31007213 is 31270013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 27019204 + 3988009 = 5198^2 + 1997^2 .

It is a cyclic number.

It is not a de Polignac number, because 31007213 - 2⁶ = 31007149 is a prime.

It is a super-2 number, since 2×31007213² = 1922894516054738, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 31007191 and 31007200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31007219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15503606 + 15503607.

It is an arithmetic number, because the mean of its divisors is an integer number (15503607).

Almost surely, 2^31007213 is an apocalyptic number.

It is an amenable number.

31007213 is a deficient number, since it is larger than the sum of its proper divisors (1).

31007213 is an equidigital number, since it uses as much as digits as its factorization.

31007213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 126, while the sum is 17.

The square root of 31007213 is about 5568.4120716772. The cubic root of 31007213 is about 314.1624276278.

Adding to 31007213 its reverse (31270013), we get a palindrome (62277226).

The spelling of 31007213 in words is "thirty-one million, seven thousand, two hundred thirteen".