66872138 has 8 divisors (see below), whose sum is σ = 102641088. Its totient is φ = 32658444.

The previous prime is 66872129. The next prime is 66872147. The reversal of 66872138 is 83127866.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66872129) and next prime (66872147).

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

It is a junction number, because it is equal to n+sod(n) for n = 66872095 and 66872104.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 388706 + ... + 388877.

It is an arithmetic number, because the mean of its divisors is an integer number (12830136).

Almost surely, 2^66872138 is an apocalyptic number.

66872138 is a deficient number, since it is larger than the sum of its proper divisors (35768950).

66872138 is a wasteful number, since it uses less digits than its factorization.

66872138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777628.

The product of its digits is 96768, while the sum is 41.

The square root of 66872138 is about 8177.5386272399. The cubic root of 66872138 is about 405.8962785186.

It can be divided in two parts, 668 and 72138, that multiplied together give a palindrome (48188184).

The spelling of 66872138 in words is "sixty-six million, eight hundred seventy-two thousand, one hundred thirty-eight".