31781341 has 2 divisors, whose sum is σ = 31781342. Its totient is φ = 31781340.

The previous prime is 31781339. The next prime is 31781359. The reversal of 31781341 is 14318713.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31125241 + 656100 = 5579^2 + 810^2 .

It is a cyclic number.

It is not a de Polignac number, because 31781341 - 2¹ = 31781339 is a prime.

Together with 31781339, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31781441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15890670 + 15890671.

It is an arithmetic number, because the mean of its divisors is an integer number (15890671).

Almost surely, 2^31781341 is an apocalyptic number.

It is an amenable number.

31781341 is a deficient number, since it is larger than the sum of its proper divisors (1).

31781341 is an equidigital number, since it uses as much as digits as its factorization.

31781341 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 28.

The square root of 31781341 is about 5637.4942128573. The cubic root of 31781341 is about 316.7554330407.

The spelling of 31781341 in words is "thirty-one million, seven hundred eighty-one thousand, three hundred forty-one".