2171506345 has 4 divisors (see below), whose sum is σ = 2605807620. Its totient is φ = 1737205072.

The previous prime is 2171506331. The next prime is 2171506349. The reversal of 2171506345 is 5436051712.

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 830188969 + 1341317376 = 28813^2 + 36624^2 .

It is a cyclic number.

It is not a de Polignac number, because 2171506345 - 2¹¹ = 2171504297 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2171506345.

It is not an unprimeable number, because it can be changed into a prime (2171506349) 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, 217150630 + ... + 217150639.

It is an arithmetic number, because the mean of its divisors is an integer number (651451905).

Almost surely, 2^2171506345 is an apocalyptic number.

It is an amenable number.

2171506345 is a deficient number, since it is larger than the sum of its proper divisors (434301275).

2171506345 is an equidigital number, since it uses as much as digits as its factorization.

2171506345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434301274.

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 2171506345 is about 46599.4242990190. The cubic root of 2171506345 is about 1294.9520899773.

The spelling of 2171506345 in words is "two billion, one hundred seventy-one million, five hundred six thousand, three hundred forty-five".