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31439 = 149211
BaseRepresentation
bin111101011001111
31121010102
413223033
52001224
6401315
7160442
oct75317
947112
1031439
1121691
121623b
1311405
14b659
1594ae
hex7acf

31439 has 4 divisors (see below), whose sum is σ = 31800. Its totient is φ = 31080.

The previous prime is 31397. The next prime is 31469. The reversal of 31439 is 93413.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 93413 = 109857.

It is a cyclic number.

It is not a de Polignac number, because 31439 - 28 = 31183 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 31439.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31439.

It is not an unprimeable number, because it can be changed into a prime (31469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44 + ... + 254.

It is an arithmetic number, because the mean of its divisors is an integer number (7950).

231439 is an apocalyptic number.

31439 is a deficient number, since it is larger than the sum of its proper divisors (361).

31439 is a wasteful number, since it uses less digits than its factorization.

31439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360.

The product of its digits is 324, while the sum is 20.

The square root of 31439 is about 177.3104621843. The cubic root of 31439 is about 31.5613986807.

It can be divided in two parts, 314 and 39, that multiplied together give a triangular number (12246 = T156).

The spelling of 31439 in words is "thirty-one thousand, four hundred thirty-nine".

Divisors: 1 149 211 31439