3855443661 has 12 divisors (see below), whose sum is σ = 5570845020. Its totient is φ = 2569432320.

The previous prime is 3855443639. The next prime is 3855443671. The reversal of 3855443661 is 1663445583.

3855443661 is a `hidden beast` number, since 3 + 8 + 554 + 4 + 36 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3635366436 + 220077225 = 60294^2 + 14835^2 .

It is not a de Polignac number, because 3855443661 - 2¹⁰ = 3855442637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3855443671) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 43066 + ... + 97803.

It is an arithmetic number, because the mean of its divisors is an integer number (464237085).

Almost surely, 2^3855443661 is an apocalyptic number.

It is an amenable number.

3855443661 is a deficient number, since it is larger than the sum of its proper divisors (1715401359).

3855443661 is a wasteful number, since it uses less digits than its factorization.

3855443661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143916 (or 143913 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 45.

The square root of 3855443661 is about 62092.2190052828. The cubic root of 3855443661 is about 1568.0435501156.

It can be divided in two parts, 38554 and 43661, that added together give a triangular number (82215 = T₄₀₅).

The spelling of 3855443661 in words is "three billion, eight hundred fifty-five million, four hundred forty-three thousand, six hundred sixty-one".