31320997 has 2 divisors, whose sum is σ = 31320998. Its totient is φ = 31320996.

The previous prime is 31320977. The next prime is 31321013. The reversal of 31320997 is 79902313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20784481 + 10536516 = 4559^2 + 3246^2 .

It is a cyclic number.

It is not a de Polignac number, because 31320997 - 2¹⁹ = 30796709 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31320937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15660498 + 15660499.

It is an arithmetic number, because the mean of its divisors is an integer number (15660499).

Almost surely, 2^31320997 is an apocalyptic number.

It is an amenable number.

31320997 is a deficient number, since it is larger than the sum of its proper divisors (1).

31320997 is an equidigital number, since it uses as much as digits as its factorization.

31320997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 31320997 is about 5596.5165058275. The cubic root of 31320997 is about 315.2186170313.

The spelling of 31320997 in words is "thirty-one million, three hundred twenty thousand, nine hundred ninety-seven".