6666778339450 has 24 divisors (see below), whose sum is σ = 12400296634908. Its totient is φ = 2666692212480.

The previous prime is 6666778339411. The next prime is 6666778339457. The reversal of 6666778339450 is 549338776666.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3762129623641 + 2904648715809 = 1939621^2 + 1704303^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 6666778339450.

It is not an unprimeable number, because it can be changed into a prime (6666778339457) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8081314 + ... + 8867986.

Almost surely, 2^{6666778339450} is an apocalyptic number.

6666778339450 is a deficient number, since it is larger than the sum of its proper divisors (5733518295458).

6666778339450 is a wasteful number, since it uses less digits than its factorization.

6666778339450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956178 (or 956173 counting only the distinct ones).

The product of its (nonzero) digits is 823011840, while the sum is 70.

The spelling of 6666778339450 in words is "six trillion, six hundred sixty-six billion, seven hundred seventy-eight million, three hundred thirty-nine thousand, four hundred fifty".