2166497280 has 280 divisors, whose sum is σ = 7778713932. Its totient is φ = 576847872.

The previous prime is 2166497273. The next prime is 2166497293. The reversal of 2166497280 is 827946612.

It is a happy number.

2166497280 is a `hidden beast` number, since 21 + 66 + 497 + 2 + 80 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2070614016 + 95883264 = 45504^2 + 9792^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3317434 + ... + 3318086.

Almost surely, 2^2166497280 is an apocalyptic number.

2166497280 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 2166497280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3889356966).

2166497280 is an abundant number, since it is smaller than the sum of its proper divisors (5612216652).

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

2166497280 is an frugal number, since it uses more digits than its factorization.

2166497280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 696 (or 663 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 2166497280 is about 46545.6472723283. The cubic root of 2166497280 is about 1293.9556245318.

The spelling of 2166497280 in words is "two billion, one hundred sixty-six million, four hundred ninety-seven thousand, two hundred eighty".