31381739 has 2 divisors, whose sum is σ = 31381740. Its totient is φ = 31381738.

The previous prime is 31381717. The next prime is 31381747. The reversal of 31381739 is 93718313.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31381739 - 2¹⁶ = 31316203 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 31381699 and 31381708.

It is not a weakly prime, because it can be changed into another prime (31381789) 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, 15690869 + 15690870.

It is an arithmetic number, because the mean of its divisors is an integer number (15690870).

Almost surely, 2^31381739 is an apocalyptic number.

31381739 is a deficient number, since it is larger than the sum of its proper divisors (1).

31381739 is an equidigital number, since it uses as much as digits as its factorization.

31381739 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 35.

The square root of 31381739 is about 5601.9406458834. The cubic root of 31381739 is about 315.4222572607.

The spelling of 31381739 in words is "thirty-one million, three hundred eighty-one thousand, seven hundred thirty-nine".