2161820293 has 4 divisors (see below), whose sum is σ = 2162181420. Its totient is φ = 2161459168.

The previous prime is 2161820291. The next prime is 2161820299. The reversal of 2161820293 is 3920281612.

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 673558209 + 1488262084 = 25953^2 + 38578^2 .

It is a cyclic number.

It is not a de Polignac number, because 2161820293 - 2¹ = 2161820291 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 (2161820291) 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, 171430 + ... + 183607.

It is an arithmetic number, because the mean of its divisors is an integer number (540545355).

Almost surely, 2^2161820293 is an apocalyptic number.

It is an amenable number.

2161820293 is a deficient number, since it is larger than the sum of its proper divisors (361127).

2161820293 is an equidigital number, since it uses as much as digits as its factorization.

2161820293 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361126.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 2161820293 is about 46495.3792650410. The cubic root of 2161820293 is about 1293.0238326541.

The spelling of 2161820293 in words is "two billion, one hundred sixty-one million, eight hundred twenty thousand, two hundred ninety-three".