2161801559 has 4 divisors (see below), whose sum is σ = 2162159616. Its totient is φ = 2161443504.

The previous prime is 2161801541. The next prime is 2161801573. The reversal of 2161801559 is 9551081612.

2161801559 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.

It is a cyclic number.

It is not a de Polignac number, because 2161801559 - 2¹⁶ = 2161736023 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 (2161801529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169814 + ... + 182099.

It is an arithmetic number, because the mean of its divisors is an integer number (540539904).

Almost surely, 2^2161801559 is an apocalyptic number.

2161801559 is a deficient number, since it is larger than the sum of its proper divisors (358057).

2161801559 is an equidigital number, since it uses as much as digits as its factorization.

2161801559 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 358056.

The product of its (nonzero) digits is 21600, while the sum is 38.

The square root of 2161801559 is about 46495.1778037250. The cubic root of 2161801559 is about 1293.0200975952.

The spelling of 2161801559 in words is "two billion, one hundred sixty-one million, eight hundred one thousand, five hundred fifty-nine".