3661566777 has 48 divisors (see below), whose sum is σ = 6193032768. Its totient is φ = 2059914240.

The previous prime is 3661566763. The next prime is 3661566793. The reversal of 3661566777 is 7776651663.

It is a happy number.

3661566777 is a `hidden beast` number, since 3 + 6 + 6 + 1 + 566 + 7 + 77 = 666.

It is not a de Polignac number, because 3661566777 - 2⁸ = 3661566521 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3661566737) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 107958 + ... + 137760.

It is an arithmetic number, because the mean of its divisors is an integer number (129021516).

Almost surely, 2^3661566777 is an apocalyptic number.

It is an amenable number.

3661566777 is a deficient number, since it is larger than the sum of its proper divisors (2531465991).

3661566777 is a wasteful number, since it uses less digits than its factorization.

3661566777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29910 (or 29907 counting only the distinct ones).

The product of its digits is 6667920, while the sum is 54.

The square root of 3661566777 is about 60510.8814759792. The cubic root of 3661566777 is about 1541.3064161620.

The spelling of 3661566777 in words is "three billion, six hundred sixty-one million, five hundred sixty-six thousand, seven hundred seventy-seven".