20221840 has 40 divisors (see below), whose sum is σ = 49784760. Its totient is φ = 7612416.

The previous prime is 20221819. The next prime is 20221843. The reversal of 20221840 is 4812202.

It can be written as a sum of positive squares in 4 ways, for example, as 2108304 + 18113536 = 1452^2 + 4256^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (20221843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6075 + ... + 8794.

It is an arithmetic number, because the mean of its divisors is an integer number (1244619).

Almost surely, 2^20221840 is an apocalyptic number.

20221840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20221840 is an abundant number, since it is smaller than the sum of its proper divisors (29562920).

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

20221840 is a wasteful number, since it uses less digits than its factorization.

20221840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14899 (or 14893 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 20221840 is about 4496.8700225824. The cubic root of 20221840 is about 272.4416843481.

The spelling of 20221840 in words is "twenty million, two hundred twenty-one thousand, eight hundred forty".