43820821 has 8 divisors (see below), whose sum is σ = 50320800. Its totient is φ = 37740240.

The previous prime is 43820809. The next prime is 43820831. The reversal of 43820821 is 12802834.

43820821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 43820821 - 2¹⁵ = 43788053 is a prime.

It is a super-2 number, since 2×43820821² = 3840528706228082, 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 43820821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43820801) 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 7 ways as a sum of consecutive naturals, for example, 104626 + ... + 105043.

It is an arithmetic number, because the mean of its divisors is an integer number (6290100).

Almost surely, 2^43820821 is an apocalyptic number.

It is an amenable number.

43820821 is a deficient number, since it is larger than the sum of its proper divisors (6499979).

43820821 is a wasteful number, since it uses less digits than its factorization.

43820821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209699.

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 43820821 is about 6619.7296772602. The cubic root of 43820821 is about 352.5549661951.

The spelling of 43820821 in words is "forty-three million, eight hundred twenty thousand, eight hundred twenty-one".