31431749 has 2 divisors, whose sum is σ = 31431750. Its totient is φ = 31431748.

The previous prime is 31431739. The next prime is 31431781. The reversal of 31431749 is 94713413.

It is an a-pointer prime, because the next prime (31431781) can be obtained adding 31431749 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28281124 + 3150625 = 5318^2 + 1775^2 .

It is a cyclic number.

It is not a de Polignac number, because 31431749 - 2⁴ = 31431733 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 (31431739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15715874 + 15715875.

It is an arithmetic number, because the mean of its divisors is an integer number (15715875).

Almost surely, 2^31431749 is an apocalyptic number.

It is an amenable number.

31431749 is a deficient number, since it is larger than the sum of its proper divisors (1).

31431749 is an equidigital number, since it uses as much as digits as its factorization.

31431749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 32.

The square root of 31431749 is about 5606.4025007129. The cubic root of 31431749 is about 315.5897208420.

The spelling of 31431749 in words is "thirty-one million, four hundred thirty-one thousand, seven hundred forty-nine".