42135281 has 4 divisors (see below), whose sum is σ = 42552564. Its totient is φ = 41718000.

The previous prime is 42135277. The next prime is 42135283. The reversal of 42135281 is 18253124.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 41165056 + 970225 = 6416^2 + 985^2 .

It is a cyclic number.

It is not a de Polignac number, because 42135281 - 2² = 42135277 is a prime.

It is a super-2 number, since 2×42135281² = 3550763809897922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 42135281.

It is not an unprimeable number, because it can be changed into a prime (42135283) 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, 208490 + ... + 208691.

It is an arithmetic number, because the mean of its divisors is an integer number (10638141).

Almost surely, 2^42135281 is an apocalyptic number.

It is an amenable number.

42135281 is a deficient number, since it is larger than the sum of its proper divisors (417283).

42135281 is a wasteful number, since it uses less digits than its factorization.

42135281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417282.

The product of its digits is 1920, while the sum is 26.

The square root of 42135281 is about 6491.1694632015. The cubic root of 42135281 is about 347.9754711429.

The spelling of 42135281 in words is "forty-two million, one hundred thirty-five thousand, two hundred eighty-one".