2661216084 has 18 divisors (see below), whose sum is σ = 6726962970. Its totient is φ = 887072016.

The previous prime is 2661216079. The next prime is 2661216101. The reversal of 2661216084 is 4806121662.

2661216084 is a `hidden beast` number, since 26 + 6 + 1 + 21 + 608 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2278152900 + 383063184 = 47730^2 + 19572^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 73922669 = 2661216084 / (2 + 6 + 6 + 1 + 2 + 1 + 6 + 0 + 8 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36961299 + ... + 36961370.

It is an arithmetic number, because the mean of its divisors is an integer number (373720165).

Almost surely, 2^2661216084 is an apocalyptic number.

It is an amenable number.

2661216084 is an abundant number, since it is smaller than the sum of its proper divisors (4065746886).

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

2661216084 is a wasteful number, since it uses less digits than its factorization.

2661216084 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73922679 (or 73922674 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 2661216084 is about 51586.9759144690. The cubic root of 2661216084 is about 1385.7770985157. Note that the first 3 decimals are identical.

The spelling of 2661216084 in words is "two billion, six hundred sixty-one million, two hundred sixteen thousand, eighty-four".