42858721 has 4 divisors (see below), whose sum is σ = 43585200. Its totient is φ = 42132244.

The previous prime is 42858707. The next prime is 42858733. The reversal of 42858721 is 12785824.

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 42858721 - 2¹¹ = 42856673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42858791) 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, 363151 + ... + 363268.

It is an arithmetic number, because the mean of its divisors is an integer number (10896300).

Almost surely, 2^42858721 is an apocalyptic number.

It is an amenable number.

42858721 is a deficient number, since it is larger than the sum of its proper divisors (726479).

42858721 is an equidigital number, since it uses as much as digits as its factorization.

42858721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 726478.

The product of its digits is 35840, while the sum is 37.

The square root of 42858721 is about 6546.6572386219. The cubic root of 42858721 is about 349.9556977939.

The spelling of 42858721 in words is "forty-two million, eight hundred fifty-eight thousand, seven hundred twenty-one".