31340381 has 2 divisors, whose sum is σ = 31340382. Its totient is φ = 31340380.

The previous prime is 31340317. The next prime is 31340417. The reversal of 31340381 is 18304313.

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., 24344356 + 6996025 = 4934^2 + 2645^2 .

It is a cyclic number.

It is not a de Polignac number, because 31340381 - 2⁶ = 31340317 is a prime.

It is a super-2 number, since 2×31340381² = 1964438962450322, 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 (31340081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15670190 + 15670191.

It is an arithmetic number, because the mean of its divisors is an integer number (15670191).

Almost surely, 2^31340381 is an apocalyptic number.

It is an amenable number.

31340381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31340381 is an equidigital number, since it uses as much as digits as its factorization.

31340381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 31340381 is about 5598.2480295178. The cubic root of 31340381 is about 315.2836313262.

Adding to 31340381 its reverse (18304313), we get a palindrome (49644694).

The spelling of 31340381 in words is "thirty-one million, three hundred forty thousand, three hundred eighty-one".