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31291 = 132983

31291 has 8 divisors (see below), whose sum is σ = 35280. Its totient is φ = 27552.

The previous prime is 31277. The next prime is 31307. The reversal of 31291 is 19213.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 31291 - 25 = 31259 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (31231) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 336 + ... + 418.

It is an arithmetic number, because the mean of its divisors is an integer number (4410).

231291 is an apocalyptic number.

31291 is a deficient number, since it is larger than the sum of its proper divisors (3989).

31291 is a wasteful number, since it uses less digits than its factorization.

31291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125.

The product of its digits is 54, while the sum is 16.

The square root of 31291 is about 176.8926227970. The cubic root of 31291 is about 31.5117953642.

The spelling of 31291 in words is "thirty-one thousand, two hundred ninety-one".

Divisors: 1 13 29 83 377 1079 2407 31291