72666139 has 16 divisors (see below), whose sum is σ = 92323840. Its totient is φ = 55637280.

The previous prime is 72666137. The next prime is 72666149. The reversal of 72666139 is 93166627.

It is a cyclic number.

It is not a de Polignac number, because 72666139 - 2¹ = 72666137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (72666133) 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, 10059 + ... + 15700.

It is an arithmetic number, because the mean of its divisors is an integer number (5770240).

Almost surely, 2^72666139 is an apocalyptic number.

72666139 is a deficient number, since it is larger than the sum of its proper divisors (19657701).

72666139 is a wasteful number, since it uses less digits than its factorization.

72666139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25810.

The product of its digits is 81648, while the sum is 40.

The square root of 72666139 is about 8524.4436182076. The cubic root of 72666139 is about 417.2958141958.

The spelling of 72666139 in words is "seventy-two million, six hundred sixty-six thousand, one hundred thirty-nine".