3861661128 has 32 divisors (see below), whose sum is σ = 10396780800. Its totient is φ = 1188203328.

The previous prime is 3861661123. The next prime is 3861661159. The reversal of 3861661128 is 8211661683.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 3861661128.

It is not an unprimeable number, because it can be changed into a prime (3861661123) 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, 6188248 + ... + 6188871.

It is an arithmetic number, because the mean of its divisors is an integer number (324899400).

Almost surely, 2^3861661128 is an apocalyptic number.

It is an amenable number.

3861661128 is an abundant number, since it is smaller than the sum of its proper divisors (6535119672).

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

3861661128 is a wasteful number, since it uses less digits than its factorization.

3861661128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12377141 (or 12377137 counting only the distinct ones).

The product of its digits is 82944, while the sum is 42.

The square root of 3861661128 is about 62142.2652306785. The cubic root of 3861661128 is about 1568.8859973039.

The spelling of 3861661128 in words is "three billion, eight hundred sixty-one million, six hundred sixty-one thousand, one hundred twenty-eight".