72666138 has 8 divisors (see below), whose sum is σ = 145332288. Its totient is φ = 24222044.

The previous prime is 72666137. The next prime is 72666149. The reversal of 72666138 is 83166627.

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

72666138 is an admirable number.

It is a super-2 number, since 2×72666138² = 10560735223670088, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 72666096 and 72666105.

It is not an unprimeable number, because it can be changed into a prime (72666133) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 6055506 + ... + 6055517.

It is an arithmetic number, because the mean of its divisors is an integer number (18166536).

Almost surely, 2^72666138 is an apocalyptic number.

72666138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

72666138 is a wasteful number, since it uses less digits than its factorization.

72666138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12111028.

The product of its digits is 72576, while the sum is 39.

The square root of 72666138 is about 8524.4435595527. The cubic root of 72666138 is about 417.2958122815.

The spelling of 72666138 in words is "seventy-two million, six hundred sixty-six thousand, one hundred thirty-eight".