2166365309 has 4 divisors (see below), whose sum is σ = 2174795004. Its totient is φ = 2157935616.

The previous prime is 2166365303. The next prime is 2166365317. The reversal of 2166365309 is 9035636612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1734972409 + 431392900 = 41653^2 + 20770^2 .

It is a cyclic number.

It is not a de Polignac number, because 2166365309 - 2⁸ = 2166365053 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 (2166365303) 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, 4214462 + ... + 4214975.

It is an arithmetic number, because the mean of its divisors is an integer number (543698751).

Almost surely, 2^2166365309 is an apocalyptic number.

It is an amenable number.

2166365309 is a deficient number, since it is larger than the sum of its proper divisors (8429695).

2166365309 is an equidigital number, since it uses as much as digits as its factorization.

2166365309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8429694.

The product of its (nonzero) digits is 174960, while the sum is 41.

The square root of 2166365309 is about 46544.2295993821. The cubic root of 2166365309 is about 1293.9293504647.

The spelling of 2166365309 in words is "two billion, one hundred sixty-six million, three hundred sixty-five thousand, three hundred nine".