42158121 has 4 divisors (see below), whose sum is σ = 56210832. Its totient is φ = 28105412.

The previous prime is 42158119. The next prime is 42158159. The reversal of 42158121 is 12185124.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 42158121 - 2¹ = 42158119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42158091 and 42158100.

It is not an unprimeable number, because it can be changed into a prime (42158101) 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, 7026351 + ... + 7026356.

It is an arithmetic number, because the mean of its divisors is an integer number (14052708).

Almost surely, 2^42158121 is an apocalyptic number.

It is an amenable number.

42158121 is a deficient number, since it is larger than the sum of its proper divisors (14052711).

42158121 is a wasteful number, since it uses less digits than its factorization.

42158121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14052710.

The product of its digits is 640, while the sum is 24.

The square root of 42158121 is about 6492.9285380327. The cubic root of 42158121 is about 348.0383347253.

The spelling of 42158121 in words is "forty-two million, one hundred fifty-eight thousand, one hundred twenty-one".