3780018661 has 8 divisors (see below), whose sum is σ = 3803023224. Its totient is φ = 3757037760.

The previous prime is 3780018637. The next prime is 3780018689. The reversal of 3780018661 is 1668100873.

3780018661 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 679644900 + 3100373761 = 26070^2 + 55681^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3780018661 - 2¹⁷ = 3779887589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3780018461) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 395835 + ... + 405271.

It is an arithmetic number, because the mean of its divisors is an integer number (475377903).

Almost surely, 2^3780018661 is an apocalyptic number.

It is an amenable number.

3780018661 is a deficient number, since it is larger than the sum of its proper divisors (23004563).

3780018661 is a wasteful number, since it uses less digits than its factorization.

3780018661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11831.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 3780018661 is about 61481.8563561641. The cubic root of 3780018661 is about 1557.7507939673.

The spelling of 3780018661 in words is "three billion, seven hundred eighty million, eighteen thousand, six hundred sixty-one".