31689337 has 2 divisors, whose sum is σ = 31689338. Its totient is φ = 31689336.

The previous prime is 31689277. The next prime is 31689367. The reversal of 31689337 is 73398613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18844281 + 12845056 = 4341^2 + 3584^2 .

It is a cyclic number.

It is not a de Polignac number, because 31689337 - 2¹¹ = 31687289 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31689337.

It is not a weakly prime, because it can be changed into another prime (31689367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15844668 + 15844669.

It is an arithmetic number, because the mean of its divisors is an integer number (15844669).

Almost surely, 2^31689337 is an apocalyptic number.

It is an amenable number.

31689337 is a deficient number, since it is larger than the sum of its proper divisors (1).

31689337 is an equidigital number, since it uses as much as digits as its factorization.

31689337 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81648, while the sum is 40.

The square root of 31689337 is about 5629.3282903025. The cubic root of 31689337 is about 316.4494785286.

The spelling of 31689337 in words is "thirty-one million, six hundred eighty-nine thousand, three hundred thirty-seven".