42157 has 2 divisors, whose sum is σ = 42158. Its totient is φ = 42156.

The previous prime is 42139. The next prime is 42169. The reversal of 42157 is 75124.

42157 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30276 + 11881 = 174^2 + 109^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42157 is a prime.

It is a plaindrome in base 8.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21078 + 21079.

It is an arithmetic number, because the mean of its divisors is an integer number (21079).

2⁴²¹⁵⁷ is an apocalyptic number.

It is an amenable number.

42157 is a deficient number, since it is larger than the sum of its proper divisors (1).

42157 is an equidigital number, since it uses as much as digits as its factorization.

42157 is an evil number, because the sum of its binary digits is even.

The product of its digits is 280, while the sum is 19.

The square root of 42157 is about 205.3216988046. The cubic root of 42157 is about 34.8035249875.

The spelling of 42157 in words is "forty-two thousand, one hundred fifty-seven".