42557 has 2 divisors, whose sum is σ = 42558. Its totient is φ = 42556.

The previous prime is 42533. The next prime is 42569. The reversal of 42557 is 75524.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42436 + 121 = 206^2 + 11^2 .

It is a cyclic number.

It is not a de Polignac number, because 42557 - 2¹² = 38461 is a prime.

It is a super-2 number, since 2×42557² = 3622196498, which contains 22 as substring.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (42577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21278 + 21279.

It is an arithmetic number, because the mean of its divisors is an integer number (21279).

2⁴²⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

42557 is a deficient number, since it is larger than the sum of its proper divisors (1).

42557 is an equidigital number, since it uses as much as digits as its factorization.

42557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1400, while the sum is 23.

The square root of 42557 is about 206.2934802654. The cubic root of 42557 is about 34.9132545720.

The spelling of 42557 in words is "forty-two thousand, five hundred fifty-seven".