66774813550 has 24 divisors (see below), whose sum is σ = 124488032256. Its totient is φ = 26648231040.

The previous prime is 66774813541. The next prime is 66774813571. The reversal of 66774813550 is 5531847766.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1520494 + ... + 1563793.

It is an arithmetic number, because the mean of its divisors is an integer number (5187001344).

Almost surely, 2^66774813550 is an apocalyptic number.

66774813550 is a deficient number, since it is larger than the sum of its proper divisors (57713218706).

66774813550 is a wasteful number, since it uses less digits than its factorization.

66774813550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3084732 (or 3084727 counting only the distinct ones).

The product of its (nonzero) digits is 4233600, while the sum is 52.

The spelling of 66774813550 in words is "sixty-six billion, seven hundred seventy-four million, eight hundred thirteen thousand, five hundred fifty".