3661555812 has 48 divisors (see below), whose sum is σ = 9199552320. Its totient is φ = 1129249792.

The previous prime is 3661555811. The next prime is 3661555813. The reversal of 3661555812 is 2185551663.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (3661555811) and next prime (3661555813).

It is not an unprimeable number, because it can be changed into a prime (3661555811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140073 + ... + 164144.

It is an arithmetic number, because the mean of its divisors is an integer number (191657340).

Almost surely, 2^3661555812 is an apocalyptic number.

It is an amenable number.

3661555812 is an abundant number, since it is smaller than the sum of its proper divisors (5537996508).

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

3661555812 is a wasteful number, since it uses less digits than its factorization.

3661555812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304300 (or 304298 counting only the distinct ones).

The product of its digits is 216000, while the sum is 42.

The square root of 3661555812 is about 60510.7908723725. The cubic root of 3661555812 is about 1541.3048776182.

The spelling of 3661555812 in words is "three billion, six hundred sixty-one million, five hundred fifty-five thousand, eight hundred twelve".