72661666 has 32 divisors (see below), whose sum is σ = 136627200. Its totient is φ = 28155600.

The previous prime is 72661661. The next prime is 72661679. The reversal of 72661666 is 66616627.

It is not an unprimeable number, because it can be changed into a prime (72661661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29461 + ... + 31831.

It is an arithmetic number, because the mean of its divisors is an integer number (4269600).

Almost surely, 2^72661666 is an apocalyptic number.

72661666 is a deficient number, since it is larger than the sum of its proper divisors (63965534).

72661666 is a wasteful number, since it uses less digits than its factorization.

72661666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2590.

The product of its digits is 108864, while the sum is 40.

The square root of 72661666 is about 8524.1812510059. The cubic root of 72661666 is about 417.2872517369.

The spelling of 72661666 in words is "seventy-two million, six hundred sixty-one thousand, six hundred sixty-six".