31751989 has 2 divisors, whose sum is σ = 31751990. Its totient is φ = 31751988.

The previous prime is 31751969. The next prime is 31752001. The reversal of 31751989 is 98915713.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20629764 + 11122225 = 4542^2 + 3335^2 .

It is a cyclic number.

It is not a de Polignac number, because 31751989 - 2¹⁵ = 31719221 is a prime.

It is a super-2 number, since 2×31751989² = 2016377610912242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31751959) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15875994 + 15875995.

It is an arithmetic number, because the mean of its divisors is an integer number (15875995).

Almost surely, 2^31751989 is an apocalyptic number.

It is an amenable number.

31751989 is a deficient number, since it is larger than the sum of its proper divisors (1).

31751989 is an equidigital number, since it uses as much as digits as its factorization.

31751989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 68040, while the sum is 43.

The square root of 31751989 is about 5634.8903272380. The cubic root of 31751989 is about 316.6578887071.

The spelling of 31751989 in words is "thirty-one million, seven hundred fifty-one thousand, nine hundred eighty-nine".