1865000221 has 6 divisors (see below), whose sum is σ = 2169490110. Its totient is φ = 1598571576.

The previous prime is 1865000219. The next prime is 1865000227. The reversal of 1865000221 is 1220005681.

It can be written as a sum of positive squares in only one way, i.e., 1289528100 + 575472121 = 35910^2 + 23989^2 .

It is not a de Polignac number, because 1865000221 - 2¹ = 1865000219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1865000227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 19030566 + ... + 19030663.

It is an arithmetic number, because the mean of its divisors is an integer number (361581685).

Almost surely, 2^1865000221 is an apocalyptic number.

It is an amenable number.

1865000221 is a deficient number, since it is larger than the sum of its proper divisors (304489889).

1865000221 is an equidigital number, since it uses as much as digits as its factorization.

1865000221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38061243 (or 38061236 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 1865000221 is about 43185.6483220989. The cubic root of 1865000221 is about 1230.9099884625.

The spelling of 1865000221 in words is "one billion, eight hundred sixty-five million, two hundred twenty-one", and thus it is an aban number.