31457 has 4 divisors (see below), whose sum is σ = 31920. Its totient is φ = 30996.

The previous prime is 31397. The next prime is 31469. The reversal of 31457 is 75413.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75413 = 13 ⋅5801.

It is a cyclic number.

It is not a de Polignac number, because 31457 - 2⁶ = 31393 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31457.

It is not an unprimeable number, because it can be changed into a prime (31477) 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, 107 + ... + 272.

It is an arithmetic number, because the mean of its divisors is an integer number (7980).

2³¹⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

31457 is a deficient number, since it is larger than the sum of its proper divisors (463).

31457 is an equidigital number, since it uses as much as digits as its factorization.

It is an anagram of its base 8 representation: 31457 = (75341)₈.

31457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462.

The product of its digits is 420, while the sum is 20.

The square root of 31457 is about 177.3612133472. The cubic root of 31457 is about 31.5674208908.

Subtracting 31457 from its reverse (75413), we obtain a triangular number (43956 = T₂₉₆).

It can be divided in two parts, 3 and 1457, that multiplied together give a triangular number (4371 = T₉₃).

The spelling of 31457 in words is "thirty-one thousand, four hundred fifty-seven".