31489 has 2 divisors, whose sum is σ = 31490. Its totient is φ = 31488.

The previous prime is 31481. The next prime is 31511. The reversal of 31489 is 98413.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 27889 + 3600 = 167^2 + 60^2 .

It is a cyclic number.

It is not a de Polignac number, because 31489 - 2³ = 31481 is a prime.

31489 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (31481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15744 + 15745.

It is an arithmetic number, because the mean of its divisors is an integer number (15745).

It is a Proth number, since it is equal to 123 ⋅ 2⁸ + 1 and 123 < 2⁸.

2³¹⁴⁸⁹ is an apocalyptic number.

It is an amenable number.

31489 is a deficient number, since it is larger than the sum of its proper divisors (1).

31489 is an equidigital number, since it uses as much as digits as its factorization.

31489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 31489 is about 177.4514017978. The cubic root of 31489 is about 31.5781213722.

Subtracting from 31489 its product of digits (864), we obtain a square (30625 = 175²).

The spelling of 31489 in words is "thirty-one thousand, four hundred eighty-nine".