2159645 has 4 divisors (see below), whose sum is σ = 2591580. Its totient is φ = 1727712.

The previous prime is 2159639. The next prime is 2159669. The reversal of 2159645 is 5469512.

It is a happy number.

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 574564 + 1585081 = 758^2 + 1259^2 .

It is a cyclic number.

It is not a de Polignac number, because 2159645 - 2¹⁰ = 2158621 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 215960 + ... + 215969.

It is an arithmetic number, because the mean of its divisors is an integer number (647895).

2^2159645 is an apocalyptic number.

It is an amenable number.

2159645 is a deficient number, since it is larger than the sum of its proper divisors (431935).

2159645 is an equidigital number, since it uses as much as digits as its factorization.

2159645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 431934.

The product of its digits is 10800, while the sum is 32.

The square root of 2159645 is about 1469.5730672546. The cubic root of 2159645 is about 129.2589993073.

The spelling of 2159645 in words is "two million, one hundred fifty-nine thousand, six hundred forty-five".