2181081164 has 24 divisors (see below), whose sum is σ = 4048022160. Its totient is φ = 1024713216.

The previous prime is 2181081151. The next prime is 2181081211. The reversal of 2181081164 is 4611801812.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 2181081164.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16184 + ... + 68000.

It is an arithmetic number, because the mean of its divisors is an integer number (168667590).

Almost surely, 2^2181081164 is an apocalyptic number.

It is an amenable number.

2181081164 is a deficient number, since it is larger than the sum of its proper divisors (1866940996).

2181081164 is a wasteful number, since it uses less digits than its factorization.

2181081164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52457 (or 52455 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 32.

The square root of 2181081164 is about 46702.0466789198. The cubic root of 2181081164 is about 1296.8525760745.

Adding to 2181081164 its reverse (4611801812), we get a palindrome (6792882976).

The spelling of 2181081164 in words is "two billion, one hundred eighty-one million, eighty-one thousand, one hundred sixty-four".