31591493 has 2 divisors, whose sum is σ = 31591494. Its totient is φ = 31591492.

The previous prime is 31591477. The next prime is 31591499. The reversal of 31591493 is 39419513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31550689 + 40804 = 5617^2 + 202^2 .

It is a cyclic number.

It is not a de Polignac number, because 31591493 - 2⁴ = 31591477 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31591499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15795746 + 15795747.

It is an arithmetic number, because the mean of its divisors is an integer number (15795747).

Almost surely, 2^31591493 is an apocalyptic number.

It is an amenable number.

31591493 is a deficient number, since it is larger than the sum of its proper divisors (1).

31591493 is an equidigital number, since it uses as much as digits as its factorization.

31591493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14580, while the sum is 35.

The square root of 31591493 is about 5620.6310143969. The cubic root of 31591493 is about 316.1234529389.

The spelling of 31591493 in words is "thirty-one million, five hundred ninety-one thousand, four hundred ninety-three".