66778339450 has 12 divisors (see below), whose sum is σ = 124207711470. Its totient is φ = 26711335760.

The previous prime is 66778339423. The next prime is 66778339559. The reversal of 66778339450 is 5493387766.

66778339450 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 24081142761 + 42697196689 = 155181^2 + 206633^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 667783345 + ... + 667783444.

Almost surely, 2^66778339450 is an apocalyptic number.

66778339450 is a deficient number, since it is larger than the sum of its proper divisors (57429372020).

66778339450 is a wasteful number, since it uses less digits than its factorization.

66778339450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1335566801 (or 1335566796 counting only the distinct ones).

The product of its (nonzero) digits is 22861440, while the sum is 58.

The spelling of 66778339450 in words is "sixty-six billion, seven hundred seventy-eight million, three hundred thirty-nine thousand, four hundred fifty".