42236821 has 4 divisors (see below), whose sum is σ = 46076544. Its totient is φ = 38397100.

The previous prime is 42236773. The next prime is 42236833. The reversal of 42236821 is 12863224.

42236821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 42236821 - 2⁹ = 42236309 is a prime.

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 42236821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42236521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1919845 + ... + 1919866.

It is an arithmetic number, because the mean of its divisors is an integer number (11519136).

Almost surely, 2^42236821 is an apocalyptic number.

It is an amenable number.

42236821 is a deficient number, since it is larger than the sum of its proper divisors (3839723).

42236821 is a wasteful number, since it uses less digits than its factorization.

42236821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3839722.

The product of its digits is 4608, while the sum is 28.

The square root of 42236821 is about 6498.9861517009. The cubic root of 42236821 is about 348.2547706089.

The spelling of 42236821 in words is "forty-two million, two hundred thirty-six thousand, eight hundred twenty-one".