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31357 is a prime number

31357 has 2 divisors, whose sum is σ = 31358. Its totient is φ = 31356.

The previous prime is 31337. The next prime is 31379. The reversal of 31357 is 75313.

Subtracting 31357 from its reverse (75313), we obtain a triangular number (43956 = T296).

It can be divided in two parts, 3135 and 7, that multiplied together give a triangular number (21945 = T209).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29241 + 2116 = 171^2 + 46^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-31357 is a prime.

It is a super-2 number, since 2×313572 = 1966522898, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31307) 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 as a sum of consecutive naturals, namely, 15678 + 15679.

It is an arithmetic number, because the mean of its divisors is an integer number (15679).

231357 is an apocalyptic number.

It is an amenable number.

31357 is a deficient number, since it is larger than the sum of its proper divisors (1).

31357 is an equidigital number, since it uses as much as digits as its factorization.

31357 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 315, while the sum is 19.

The square root of 31357 is about 177.0790783803. The cubic root of 31357 is about 31.5339350419.

The spelling of 31357 in words is "thirty-one thousand, three hundred fifty-seven".