31301381 has 2 divisors, whose sum is σ = 31301382. Its totient is φ = 31301380.

The previous prime is 31301363. The next prime is 31301393. The reversal of 31301381 is 18310313.

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., 19802500 + 11498881 = 4450^2 + 3391^2 .

It is a cyclic number.

It is not a de Polignac number, because 31301381 - 2⁶ = 31301317 is a prime.

It is a super-2 number, since 2×31301381² = 1959552905014322, 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 (31301581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15650690 + 15650691.

It is an arithmetic number, because the mean of its divisors is an integer number (15650691).

Almost surely, 2^31301381 is an apocalyptic number.

It is an amenable number.

31301381 is a deficient number, since it is larger than the sum of its proper divisors (1).

31301381 is an equidigital number, since it uses as much as digits as its factorization.

31301381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 31301381 is about 5594.7637126156. The cubic root of 31301381 is about 315.1527972907.

Adding to 31301381 its reverse (18310313), we get a palindrome (49611694).

The spelling of 31301381 in words is "thirty-one million, three hundred one thousand, three hundred eighty-one".