31961399 has 2 divisors, whose sum is σ = 31961400. Its totient is φ = 31961398.

The previous prime is 31961389. The next prime is 31961429. The reversal of 31961399 is 99316913.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31961399 - 2⁴ = 31961383 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31961339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15980699 + 15980700.

It is an arithmetic number, because the mean of its divisors is an integer number (15980700).

Almost surely, 2^31961399 is an apocalyptic number.

31961399 is a deficient number, since it is larger than the sum of its proper divisors (1).

31961399 is an equidigital number, since it uses as much as digits as its factorization.

31961399 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39366, while the sum is 41.

The square root of 31961399 is about 5653.4413413425. The cubic root of 31961399 is about 317.3525022209.

The spelling of 31961399 in words is "thirty-one million, nine hundred sixty-one thousand, three hundred ninety-nine".