31949381 has 2 divisors, whose sum is σ = 31949382. Its totient is φ = 31949380.

The previous prime is 31949377. The next prime is 31949383. The reversal of 31949381 is 18394913.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19936225 + 12013156 = 4465^2 + 3466^2 .

It is a cyclic number.

It is not a de Polignac number, because 31949381 - 2² = 31949377 is a prime.

It is a super-2 number, since 2×31949381² = 2041525892566322, which contains 22 as substring.

Together with 31949383, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31949383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15974690 + 15974691.

It is an arithmetic number, because the mean of its divisors is an integer number (15974691).

Almost surely, 2^31949381 is an apocalyptic number.

It is an amenable number.

31949381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31949381 is an equidigital number, since it uses as much as digits as its factorization.

31949381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23328, while the sum is 38.

The square root of 31949381 is about 5652.3783489784. The cubic root of 31949381 is about 317.3127206862.

The spelling of 31949381 in words is "thirty-one million, nine hundred forty-nine thousand, three hundred eighty-one".