2161816740 has 36 divisors (see below), whose sum is σ = 6557511324. Its totient is φ = 576484416.

The previous prime is 2161816711. The next prime is 2161816763. The reversal of 2161816740 is 476181612.

It is a happy number.

2161816740 is a `hidden beast` number, since 21 + 618 + 16 + 7 + 4 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1648522404 + 513294336 = 40602^2 + 22656^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 2161816695 and 2161816704.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6004867 + ... + 6005226.

Almost surely, 2^2161816740 is an apocalyptic number.

2161816740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2161816740 is an abundant number, since it is smaller than the sum of its proper divisors (4395694584).

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

2161816740 is a wasteful number, since it uses less digits than its factorization.

2161816740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12010108 (or 12010103 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 2161816740 is about 46495.3410569274. The cubic root of 2161816740 is about 1293.0231242825.

The spelling of 2161816740 in words is "two billion, one hundred sixty-one million, eight hundred sixteen thousand, seven hundred forty".