42100 has 18 divisors (see below), whose sum is σ = 91574. Its totient is φ = 16800.

The previous prime is 42089. The next prime is 42101. The reversal of 42100 is 124.

It can be written as a sum of positive squares in 3 ways, for example, as 484 + 41616 = 22^2 + 204^2 .

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42101) by changing a digit.

42100 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 111 + ... + 310.

2⁴²¹⁰⁰ is an apocalyptic number.

It is an amenable number.

42100 is an abundant number, since it is smaller than the sum of its proper divisors (49474).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

42100 is a wasteful number, since it uses less digits than its factorization.

42100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 435 (or 428 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 42100 is about 205.1828452868. The cubic root of 42100 is about 34.7878320960.

Adding to 42100 its reverse (124), we get a palindrome (42224).

The spelling of 42100 in words is "forty-two thousand, one hundred", and thus it is an iban number.