31000397 has 2 divisors, whose sum is σ = 31000398. Its totient is φ = 31000396.

The previous prime is 31000351. The next prime is 31000421. The reversal of 31000397 is 79300013.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19838116 + 11162281 = 4454^2 + 3341^2 .

It is a cyclic number.

It is not a de Polignac number, because 31000397 - 2¹⁶ = 30934861 is a prime.

It is a super-2 number, since 2×31000397² = 1922049228315218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31000337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15500198 + 15500199.

It is an arithmetic number, because the mean of its divisors is an integer number (15500199).

Almost surely, 2^31000397 is an apocalyptic number.

It is an amenable number.

31000397 is a deficient number, since it is larger than the sum of its proper divisors (1).

31000397 is an equidigital number, since it uses as much as digits as its factorization.

31000397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 567, while the sum is 23.

The square root of 31000397 is about 5567.8000143683. The cubic root of 31000397 is about 314.1394062314.

The spelling of 31000397 in words is "thirty-one million, three hundred ninety-seven", and thus it is an aban number.