2161723320 has 48 divisors (see below), whose sum is σ = 7025601960. Its totient is φ = 576459456.

The previous prime is 2161723303. The next prime is 2161723321. The reversal of 2161723320 is 233271612.

2161723320 is a `hidden beast` number, since 2 + 1 + 617 + 23 + 3 + 20 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161723321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3002034 + ... + 3002753.

Almost surely, 2^2161723320 is an apocalyptic number.

2161723320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2161723320 is an abundant number, since it is smaller than the sum of its proper divisors (4863878640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2161723320 is a wasteful number, since it uses less digits than its factorization.

2161723320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6004804 (or 6004797 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 2161723320 is about 46494.3364292900. The cubic root of 2161723320 is about 1293.0044985964.

Adding to 2161723320 its reverse (233271612), we get a palindrome (2394994932).

The spelling of 2161723320 in words is "two billion, one hundred sixty-one million, seven hundred twenty-three thousand, three hundred twenty".