72686666 has 16 divisors (see below), whose sum is σ = 123597600. Its totient is φ = 31781808.

The previous prime is 72686657. The next prime is 72686671. The reversal of 72686666 is 66668627.

It is a self number, because there is not a number n which added to its sum of digits gives 72686666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73076 + ... + 74063.

It is an arithmetic number, because the mean of its divisors is an integer number (7724850).

Almost surely, 2^72686666 is an apocalyptic number.

72686666 is a deficient number, since it is larger than the sum of its proper divisors (50910934).

72686666 is a wasteful number, since it uses less digits than its factorization.

72686666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147173.

The product of its digits is 870912, while the sum is 47.

The square root of 72686666 is about 8525.6475413895. The cubic root of 72686666 is about 417.3351035854.

The spelling of 72686666 in words is "seventy-two million, six hundred eighty-six thousand, six hundred sixty-six".