31649389 has 2 divisors, whose sum is σ = 31649390. Its totient is φ = 31649388.

The previous prime is 31649381. The next prime is 31649399. The reversal of 31649389 is 98394613.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28708164 + 2941225 = 5358^2 + 1715^2 .

It is a cyclic number.

It is not a de Polignac number, because 31649389 - 2³ = 31649381 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31649381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15824694 + 15824695.

It is an arithmetic number, because the mean of its divisors is an integer number (15824695).

Almost surely, 2^31649389 is an apocalyptic number.

It is an amenable number.

31649389 is a deficient number, since it is larger than the sum of its proper divisors (1).

31649389 is an equidigital number, since it uses as much as digits as its factorization.

31649389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 43.

The square root of 31649389 is about 5625.7789682852. The cubic root of 31649389 is about 316.3164491385.

The spelling of 31649389 in words is "thirty-one million, six hundred forty-nine thousand, three hundred eighty-nine".