3721661216 has 144 divisors (see below), whose sum is σ = 9602457984. Its totient is φ = 1385459712.

The previous prime is 3721661191. The next prime is 3721661227. The reversal of 3721661216 is 6121661273.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 640661 + ... + 646443.

It is an arithmetic number, because the mean of its divisors is an integer number (66683736).

Almost surely, 2^3721661216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3721661216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4801228992).

3721661216 is an abundant number, since it is smaller than the sum of its proper divisors (5880796768).

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

3721661216 is a wasteful number, since it uses less digits than its factorization.

3721661216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5843 (or 5822 counting only the distinct ones).

The product of its digits is 18144, while the sum is 35.

The square root of 3721661216 is about 61005.4195625274. The cubic root of 3721661216 is about 1549.6927890626.

The spelling of 3721661216 in words is "three billion, seven hundred twenty-one million, six hundred sixty-one thousand, two hundred sixteen".