1659561890 has 24 divisors (see below), whose sum is σ = 3474920412. Its totient is φ = 568992480.

The previous prime is 1659561877. The next prime is 1659561899. The reversal of 1659561890 is 981659561.

It can be written as a sum of positive squares in 2 ways, for example, as 1643248369 + 16313521 = 40537^2 + 4039^2 .

It is not an unprimeable number, because it can be changed into a prime (1659561899) 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 11 ways as a sum of consecutive naturals, for example, 1692941 + ... + 1693920.

Almost surely, 2^1659561890 is an apocalyptic number.

1659561890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1659561890 is an abundant number, since it is smaller than the sum of its proper divisors (1815358522).

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

1659561890 is a wasteful number, since it uses less digits than its factorization.

1659561890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3386882 (or 3386875 counting only the distinct ones).

The product of its (nonzero) digits is 583200, while the sum is 50.

The square root of 1659561890 is about 40737.7207266190. The cubic root of 1659561890 is about 1183.9439730496.

The spelling of 1659561890 in words is "one billion, six hundred fifty-nine million, five hundred sixty-one thousand, eight hundred ninety".