2165722880 has 72 divisors (see below), whose sum is σ = 5241363792. Its totient is φ = 857309184.

The previous prime is 2165722877. The next prime is 2165722883. The reversal of 2165722880 is 882275612.

It is an interprime number because it is at equal distance from previous prime (2165722877) and next prime (2165722883).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2165722883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115439 + ... + 132881.

Almost surely, 2^2165722880 is an apocalyptic number.

2165722880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2165722880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2620681896).

2165722880 is an abundant number, since it is smaller than the sum of its proper divisors (3075640912).

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

2165722880 is an equidigital number, since it uses as much as digits as its factorization.

2165722880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17561 (or 17547 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 41.

The square root of 2165722880 is about 46537.3278132726. The cubic root of 2165722880 is about 1293.8014342236.

The spelling of 2165722880 in words is "two billion, one hundred sixty-five million, seven hundred twenty-two thousand, eight hundred eighty".