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7957 = 73109

7957 has 4 divisors (see below), whose sum is σ = 8140. Its totient is φ = 7776.

The previous prime is 7951. The next prime is 7963. The reversal of 7957 is 7597.

It can be divided in two parts, 795 and 7, that multiplied together give a triangular number (5565 = T105).

7957 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7597 = 71107.

It is an interprime number because it is at equal distance from previous prime (7951) and next prime (7963).

It can be written as a sum of positive squares in 2 ways, for example, as 5041 + 2916 = 71^2 + 54^2 .

It is a 3-Lehmer number, since φ(7957) divides (7957-1)3.

It is a cyclic number.

It is not a de Polignac number, because 7957 - 23 = 7949 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7951) 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, 19 + ... + 127.

It is an arithmetic number, because the mean of its divisors is an integer number (2035).

It is a Poulet number, since it divides 27956-1.

27957 is an apocalyptic number.

7957 is the 73-rd pentagonal number.

7957 is the 52-nd hex number.

It is an amenable number.

7957 is a deficient number, since it is larger than the sum of its proper divisors (183).

7957 is a wasteful number, since it uses less digits than its factorization.

7957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182.

The product of its digits is 2205, while the sum is 28.

The square root of 7957 is about 89.2020179144. The cubic root of 7957 is about 19.9641022729.

The spelling of 7957 in words is "seven thousand, nine hundred fifty-seven".

Divisors: 1 73 109 7957