31920859 has 2 divisors, whose sum is σ = 31920860. Its totient is φ = 31920858.

The previous prime is 31920841. The next prime is 31920869. The reversal of 31920859 is 95802913.

It is a strong prime.

It is an emirp because it is prime and its reverse (95802913) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31920859 - 2¹⁵ = 31888091 is a prime.

It is not a weakly prime, because it can be changed into another prime (31920809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15960429 + 15960430.

It is an arithmetic number, because the mean of its divisors is an integer number (15960430).

Almost surely, 2^31920859 is an apocalyptic number.

31920859 is a deficient number, since it is larger than the sum of its proper divisors (1).

31920859 is an equidigital number, since it uses as much as digits as its factorization.

31920859 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 31920859 is about 5649.8547768947. The cubic root of 31920859 is about 317.2182682780.

The spelling of 31920859 in words is "thirty-one million, nine hundred twenty thousand, eight hundred fifty-nine".