31901489 has 2 divisors, whose sum is σ = 31901490. Its totient is φ = 31901488.

The previous prime is 31901459. The next prime is 31901497. The reversal of 31901489 is 98410913.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19651489 + 12250000 = 4433^2 + 3500^2 .

It is an emirp because it is prime and its reverse (98410913) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31901489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31901459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15950744 + 15950745.

It is an arithmetic number, because the mean of its divisors is an integer number (15950745).

Almost surely, 2^31901489 is an apocalyptic number.

It is an amenable number.

31901489 is a deficient number, since it is larger than the sum of its proper divisors (1).

31901489 is an equidigital number, since it uses as much as digits as its factorization.

31901489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 31901489 is about 5648.1403134129. The cubic root of 31901489 is about 317.1540912130.

The spelling of 31901489 in words is "thirty-one million, nine hundred one thousand, four hundred eighty-nine".