3815386661 has 4 divisors (see below), whose sum is σ = 3816706572. Its totient is φ = 3814066752.

The previous prime is 3815386621. The next prime is 3815386669. The reversal of 3815386661 is 1666835183.

3815386661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 547092100 + 3268294561 = 23390^2 + 57169^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3815386661 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 (3815386669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 655610 + ... + 661403.

It is an arithmetic number, because the mean of its divisors is an integer number (954176643).

Almost surely, 2^3815386661 is an apocalyptic number.

It is an amenable number.

3815386661 is a deficient number, since it is larger than the sum of its proper divisors (1319911).

3815386661 is a wasteful number, since it uses less digits than its factorization.

3815386661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1319910.

The product of its digits is 622080, while the sum is 47.

The square root of 3815386661 is about 61768.8162505969. The cubic root of 3815386661 is about 1562.5941197790.

The spelling of 3815386661 in words is "three billion, eight hundred fifteen million, three hundred eighty-six thousand, six hundred sixty-one".