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31979 = 113283
BaseRepresentation
bin111110011101011
31121212102
413303223
52010404
6404015
7162143
oct76353
947772
1031979
1122032
121660b
131172c
14b923
15971e
hex7ceb

31979 has 4 divisors (see below), whose sum is σ = 32376. Its totient is φ = 31584.

The previous prime is 31973. The next prime is 31981. The reversal of 31979 is 97913.

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: 97913 = 179547.

It is a cyclic number.

It is not a de Polignac number, because 31979 - 24 = 31963 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31973) 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, 29 + ... + 254.

It is an arithmetic number, because the mean of its divisors is an integer number (8094).

231979 is an apocalyptic number.

31979 is a deficient number, since it is larger than the sum of its proper divisors (397).

31979 is a wasteful number, since it uses less digits than its factorization.

31979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 396.

The product of its digits is 1701, while the sum is 29.

The square root of 31979 is about 178.8267317825. The cubic root of 31979 is about 31.7410746400.

The spelling of 31979 in words is "thirty-one thousand, nine hundred seventy-nine".

Divisors: 1 113 283 31979