31257089 has 2 divisors, whose sum is σ = 31257090. Its totient is φ = 31257088.

The previous prime is 31257077. The next prime is 31257103. The reversal of 31257089 is 98075213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22800625 + 8456464 = 4775^2 + 2908^2 .

It is an emirp because it is prime and its reverse (98075213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31257089 - 2⁴ = 31257073 is a prime.

It is a super-2 number, since 2×31257089² = 1954011225507842, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31257019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15628544 + 15628545.

It is an arithmetic number, because the mean of its divisors is an integer number (15628545).

Almost surely, 2^31257089 is an apocalyptic number.

It is an amenable number.

31257089 is a deficient number, since it is larger than the sum of its proper divisors (1).

31257089 is an equidigital number, since it uses as much as digits as its factorization.

31257089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 31257089 is about 5590.8039672305. The cubic root of 31257089 is about 315.0040782205.

The spelling of 31257089 in words is "thirty-one million, two hundred fifty-seven thousand, eighty-nine".