31319749 has 2 divisors, whose sum is σ = 31319750. Its totient is φ = 31319748.

The previous prime is 31319713. The next prime is 31319759. The reversal of 31319749 is 94791313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31024900 + 294849 = 5570^2 + 543^2 .

It is an emirp because it is prime and its reverse (94791313) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31319749 - 2¹¹ = 31317701 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31319759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15659874 + 15659875.

It is an arithmetic number, because the mean of its divisors is an integer number (15659875).

Almost surely, 2^31319749 is an apocalyptic number.

It is an amenable number.

31319749 is a deficient number, since it is larger than the sum of its proper divisors (1).

31319749 is an equidigital number, since it uses as much as digits as its factorization.

31319749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20412, while the sum is 37.

The square root of 31319749 is about 5596.4050067878. The cubic root of 31319749 is about 315.2144302972.

It can be divided in two parts, 3131 and 9749, that added together give a triangular number (12880 = T₁₆₀).

The spelling of 31319749 in words is "thirty-one million, three hundred nineteen thousand, seven hundred forty-nine".