31281634393 has 2 divisors, whose sum is σ = 31281634394. Its totient is φ = 31281634392.

The previous prime is 31281634369. The next prime is 31281634451. The reversal of 31281634393 is 39343618213.

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., 18364857289 + 12916777104 = 135517^2 + 113652^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31281634393 is a prime.

It is not a weakly prime, because it can be changed into another prime (31281634303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15640817196 + 15640817197.

It is an arithmetic number, because the mean of its divisors is an integer number (15640817197).

Almost surely, 2^31281634393 is an apocalyptic number.

It is an amenable number.

31281634393 is a deficient number, since it is larger than the sum of its proper divisors (1).

31281634393 is an equidigital number, since it uses as much as digits as its factorization.

31281634393 is an evil number, because the sum of its binary digits is even.

The product of its digits is 279936, while the sum is 43.

The spelling of 31281634393 in words is "thirty-one billion, two hundred eighty-one million, six hundred thirty-four thousand, three hundred ninety-three".