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31243 = 157199
BaseRepresentation
bin111101000001011
31120212011
413220023
51444433
6400351
7160042
oct75013
946764
1031243
1121523
12160b7
13112b4
14b559
1593cd
hex7a0b

31243 has 4 divisors (see below), whose sum is σ = 31600. Its totient is φ = 30888.

The previous prime is 31237. The next prime is 31247. The reversal of 31243 is 34213.

Adding to 31243 its reverse (34213), we get a palindrome (65456).

31243 is nontrivially palindromic in base 9.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-31243 is a prime.

It is a super-2 number, since 2×312432 = 1952250098, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31247) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 58 + ... + 256.

It is an arithmetic number, because the mean of its divisors is an integer number (7900).

231243 is an apocalyptic number.

31243 is a deficient number, since it is larger than the sum of its proper divisors (357).

31243 is a wasteful number, since it uses less digits than its factorization.

31243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356.

The product of its digits is 72, while the sum is 13.

The square root of 31243 is about 176.7568951979. The cubic root of 31243 is about 31.4956742191.

The spelling of 31243 in words is "thirty-one thousand, two hundred forty-three".

Divisors: 1 157 199 31243