31643387 has 2 divisors, whose sum is σ = 31643388. Its totient is φ = 31643386.

The previous prime is 31643369. The next prime is 31643389. The reversal of 31643387 is 78334613.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31643387 - 2¹² = 31639291 is a prime.

Together with 31643389, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31643389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15821693 + 15821694.

It is an arithmetic number, because the mean of its divisors is an integer number (15821694).

Almost surely, 2^31643387 is an apocalyptic number.

31643387 is a deficient number, since it is larger than the sum of its proper divisors (1).

31643387 is an equidigital number, since it uses as much as digits as its factorization.

31643387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 36288, while the sum is 35.

The square root of 31643387 is about 5625.2455057535. The cubic root of 31643387 is about 316.2964524244.

The spelling of 31643387 in words is "thirty-one million, six hundred forty-three thousand, three hundred eighty-seven".