31385489 has 2 divisors, whose sum is σ = 31385490. Its totient is φ = 31385488.

The previous prime is 31385461. The next prime is 31385491. The reversal of 31385489 is 98458313.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30691600 + 693889 = 5540^2 + 833^2 .

It is an emirp because it is prime and its reverse (98458313) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31385489 is a prime.

Together with 31385491, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31385429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15692744 + 15692745.

It is an arithmetic number, because the mean of its divisors is an integer number (15692745).

Almost surely, 2^31385489 is an apocalyptic number.

It is an amenable number.

31385489 is a deficient number, since it is larger than the sum of its proper divisors (1).

31385489 is an equidigital number, since it uses as much as digits as its factorization.

31385489 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 41.

The square root of 31385489 is about 5602.2753413234. The cubic root of 31385489 is about 315.4348206855.

The spelling of 31385489 in words is "thirty-one million, three hundred eighty-five thousand, four hundred eighty-nine".