43811820 has 144 divisors (see below), whose sum is σ = 148669920. Its totient is φ = 10647936.

The previous prime is 43811819. The next prime is 43811843. The reversal of 43811820 is 2811834.

43811820 = 1027² + 1028² + ... + 1066².

43811820 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 554541 + ... + 554619.

It is an arithmetic number, because the mean of its divisors is an integer number (1032430).

Almost surely, 2^43811820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 43811820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74334960).

43811820 is an abundant number, since it is smaller than the sum of its proper divisors (104858100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

43811820 is a wasteful number, since it uses less digits than its factorization.

43811820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 102 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 43811820 is about 6619.0497807465. The cubic root of 43811820 is about 352.5308257334.

The spelling of 43811820 in words is "forty-three million, eight hundred eleven thousand, eight hundred twenty".