2166289920 has 400 divisors, whose sum is σ = 8033021568. Its totient is φ = 557383680.

The previous prime is 2166289903. The next prime is 2166289967. The reversal of 2166289920 is 299826612.

2166289920 is a `hidden beast` number, since 2 + 16 + 628 + 9 + 9 + 2 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 6427992 + ... + 6428328.

Almost surely, 2^2166289920 is an apocalyptic number.

2166289920 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 2166289920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4016510784).

2166289920 is an abundant number, since it is smaller than the sum of its proper divisors (5866731648).

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

2166289920 is an equidigital number, since it uses as much as digits as its factorization.

2166289920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 2166289920 is about 46543.4197282494. The cubic root of 2166289920 is about 1293.9143408122.

The spelling of 2166289920 in words is "two billion, one hundred sixty-six million, two hundred eighty-nine thousand, nine hundred twenty".