2661216066 has 16 divisors (see below), whose sum is σ = 5913813600. Its totient is φ = 887072004.

The previous prime is 2661216053. The next prime is 2661216071. The reversal of 2661216066 is 6606121662.

It is a happy number.

2661216066 is a `hidden beast` number, since 26 + 6 + 1 + 21 + 606 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 2661216066.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24640836 + ... + 24640943.

It is an arithmetic number, because the mean of its divisors is an integer number (369613350).

Almost surely, 2^2661216066 is an apocalyptic number.

2661216066 is an abundant number, since it is smaller than the sum of its proper divisors (3252597534).

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

2661216066 is a wasteful number, since it uses less digits than its factorization.

2661216066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49281790 (or 49281784 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 2661216066 is about 51586.9757400063. The cubic root of 2661216066 is about 1385.7770953913. Note that the first 3 decimals are identical.

The spelling of 2661216066 in words is "two billion, six hundred sixty-one million, two hundred sixteen thousand, sixty-six".