72688666 has 8 divisors (see below), whose sum is σ = 109587060. Its totient is φ = 36159648.

The previous prime is 72688643. The next prime is 72688669. The reversal of 72688666 is 66688627.

It can be written as a sum of positive squares in 2 ways, for example, as 72607441 + 81225 = 8521^2 + 285^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (72688669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91851 + ... + 92638.

Almost surely, 2^72688666 is an apocalyptic number.

72688666 is a deficient number, since it is larger than the sum of its proper divisors (36898394).

72688666 is a wasteful number, since it uses less digits than its factorization.

72688666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184688.

The product of its digits is 1161216, while the sum is 49.

The square root of 72688666 is about 8525.7648337261. The cubic root of 72688666 is about 417.3389312592.

The spelling of 72688666 in words is "seventy-two million, six hundred eighty-eight thousand, six hundred sixty-six".