31382381 has 2 divisors, whose sum is σ = 31382382. Its totient is φ = 31382380.

The previous prime is 31382371. The next prime is 31382387. The reversal of 31382381 is 18328313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28526281 + 2856100 = 5341^2 + 1690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31382381 is a prime.

It is a super-2 number, since 2×31382381² = 1969707674458322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31382387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15691190 + 15691191.

It is an arithmetic number, because the mean of its divisors is an integer number (15691191).

Almost surely, 2^31382381 is an apocalyptic number.

It is an amenable number.

31382381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31382381 is an equidigital number, since it uses as much as digits as its factorization.

31382381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 29.

The square root of 31382381 is about 5601.9979471614. The cubic root of 31382381 is about 315.4244081900.

The spelling of 31382381 in words is "thirty-one million, three hundred eighty-two thousand, three hundred eighty-one".