2161861589 has 2 divisors, whose sum is σ = 2161861590. Its totient is φ = 2161861588.

The previous prime is 2161861561. The next prime is 2161861619. The reversal of 2161861589 is 9851681612.

It is a happy number.

2161861589 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2147859025 + 14002564 = 46345^2 + 3742^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161861589 - 2¹² = 2161857493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2161861519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1080930794 + 1080930795.

It is an arithmetic number, because the mean of its divisors is an integer number (1080930795).

Almost surely, 2^2161861589 is an apocalyptic number.

It is an amenable number.

2161861589 is a deficient number, since it is larger than the sum of its proper divisors (1).

2161861589 is an equidigital number, since it uses as much as digits as its factorization.

2161861589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 207360, while the sum is 47.

The square root of 2161861589 is about 46495.8233500602. The cubic root of 2161861589 is about 1293.0320658966.

The spelling of 2161861589 in words is "two billion, one hundred sixty-one million, eight hundred sixty-one thousand, five hundred eighty-nine".