72578139067666 has 16 divisors (see below), whose sum is σ = 115271767269144. Its totient is φ = 34154239060224.

The previous prime is 72578139067583. The next prime is 72578139067697. The reversal of 72578139067666 is 66676093187527.

72578139067666 is digitally balanced in base 3, 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 4 ways, for example, as 72569459350441 + 8679717225 = 8518771^2 + 93165^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1082656 + ... + 12096628.

Almost surely, 2^{72578139067666} is an apocalyptic number.

72578139067666 is a deficient number, since it is larger than the sum of its proper divisors (42693628201478).

72578139067666 is a wasteful number, since it uses less digits than its factorization.

72578139067666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11207805.

The product of its (nonzero) digits is 960180480, while the sum is 73.

The spelling of 72578139067666 in words is "seventy-two trillion, five hundred seventy-eight billion, one hundred thirty-nine million, sixty-seven thousand, six hundred sixty-six".