2181068640 has 96 divisors (see below), whose sum is σ = 7633755360. Its totient is φ = 581617152.

The previous prime is 2181068629. The next prime is 2181068693. The reversal of 2181068640 is 468601812.

2181068640 is a `hidden beast` number, since 2 + 1 + 8 + 1 + 0 + 6 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

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 = 2181068595 and 2181068604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 248119 + ... + 256758.

It is an arithmetic number, because the mean of its divisors is an integer number (79518285).

Almost surely, 2^2181068640 is an apocalyptic number.

2181068640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2181068640 is an abundant number, since it is smaller than the sum of its proper divisors (5452686720).

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

2181068640 is a wasteful number, since it uses less digits than its factorization.

2181068640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504901 (or 504887 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 2181068640 is about 46701.9125946679. The cubic root of 2181068640 is about 1296.8500938479.

The spelling of 2181068640 in words is "two billion, one hundred eighty-one million, sixty-eight thousand, six hundred forty".