66777774440 has 48 divisors (see below), whose sum is σ = 162696753900. Its totient is φ = 24656406528.

The previous prime is 66777774407. The next prime is 66777774463. The reversal of 66777774440 is 4447777766.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 25942256356 + 40835518084 = 161066^2 + 202078^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 66777774440.

It is an unprimeable number.

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, 4932425 + ... + 4945944.

Almost surely, 2^66777774440 is an apocalyptic number.

It is an amenable number.

66777774440 is an abundant number, since it is smaller than the sum of its proper divisors (95918979460).

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

66777774440 is a wasteful number, since it uses less digits than its factorization.

66777774440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9878406 (or 9878389 counting only the distinct ones).

The product of its (nonzero) digits is 38723328, while the sum is 59.

The spelling of 66777774440 in words is "sixty-six billion, seven hundred seventy-seven million, seven hundred seventy-four thousand, four hundred forty".