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1157 = 1389

1157 has 4 divisors (see below), whose sum is σ = 1260. Its totient is φ = 1056.

The previous prime is 1153. The next prime is 1163. The reversal of 1157 is 7511.

It is a Cunningham number, because it is equal to 342+1.

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 can be written as a sum of positive squares in 2 ways, for example, as 196 + 961 = 14^2 + 31^2 .

It is a cyclic number.

It is not a de Polignac number, because 1157 - 22 = 1153 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a plaindrome in base 10.

It is a nialpdrome in base 11 and base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1151) 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, 32 + ... + 57.

It is an arithmetic number, because the mean of its divisors is an integer number (315).

21157 is an apocalyptic number.

It is an amenable number.

1157 is a deficient number, since it is larger than the sum of its proper divisors (103).

1157 is an equidigital number, since it uses as much as digits as its factorization.

1157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102.

The product of its digits is 35, while the sum is 14.

The square root of 1157 is about 34.0147027034. The cubic root of 1157 is about 10.4981100151.

Adding to 1157 its reverse (7511), we get a palindrome (8668).

The spelling of 1157 in words is "one thousand, one hundred fifty-seven".

Divisors: 1 13 89 1157