2161613645 has 4 divisors (see below), whose sum is σ = 2593936380. Its totient is φ = 1729290912.

The previous prime is 2161613633. The next prime is 2161613683. The reversal of 2161613645 is 5463161612.

2161613645 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 909444649 + 1252168996 = 30157^2 + 35386^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161613645 - 2¹⁴ = 2161597261 is a prime.

It is a super-3 number, since 3×2161613645³ (a number of 29 digits) contains 333 as substring.

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, 216161360 + ... + 216161369.

It is an arithmetic number, because the mean of its divisors is an integer number (648484095).

Almost surely, 2^2161613645 is an apocalyptic number.

It is an amenable number.

2161613645 is a deficient number, since it is larger than the sum of its proper divisors (432322735).

2161613645 is an equidigital number, since it uses as much as digits as its factorization.

2161613645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432322734.

The product of its digits is 25920, while the sum is 35.

The square root of 2161613645 is about 46493.1569696015. The cubic root of 2161613645 is about 1292.9826313720.

The spelling of 2161613645 in words is "two billion, one hundred sixty-one million, six hundred thirteen thousand, six hundred forty-five".