2165091720 has 96 divisors (see below), whose sum is σ = 7139482560. Its totient is φ = 524867200.

The previous prime is 2165091659. The next prime is 2165091749. The reversal of 2165091720 is 271905612.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60036 + ... + 89075.

It is an arithmetic number, because the mean of its divisors is an integer number (74369610).

Almost surely, 2^2165091720 is an apocalyptic number.

2165091720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2165091720 is an abundant number, since it is smaller than the sum of its proper divisors (4974390840).

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

2165091720 is a wasteful number, since it uses less digits than its factorization.

2165091720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149147 (or 149132 counting only the distinct ones).

The product of its (nonzero) digits is 7560, while the sum is 33.

The square root of 2165091720 is about 46530.5460960862. The cubic root of 2165091720 is about 1293.6757371548.

The spelling of 2165091720 in words is "two billion, one hundred sixty-five million, ninety-one thousand, seven hundred twenty".