31540489 has 2 divisors, whose sum is σ = 31540490. Its totient is φ = 31540488.

The previous prime is 31540471. The next prime is 31540493. The reversal of 31540489 is 98404513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21930489 + 9610000 = 4683^2 + 3100^2 .

It is an emirp because it is prime and its reverse (98404513) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31540489 is a prime.

It is not a weakly prime, because it can be changed into another prime (31540499) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15770244 + 15770245.

It is an arithmetic number, because the mean of its divisors is an integer number (15770245).

Almost surely, 2^31540489 is an apocalyptic number.

It is an amenable number.

31540489 is a deficient number, since it is larger than the sum of its proper divisors (1).

31540489 is an equidigital number, since it uses as much as digits as its factorization.

31540489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 31540489 is about 5616.0919686202. The cubic root of 31540489 is about 315.9532357492.

It can be divided in two parts, 315 and 40489, that added together give a palindrome (40804).

The spelling of 31540489 in words is "thirty-one million, five hundred forty thousand, four hundred eighty-nine".