66288138 has 16 divisors (see below), whose sum is σ = 151515840. Its totient is φ = 18939456.

The previous prime is 66288121. The next prime is 66288191. The reversal of 66288138 is 83188266.

It is a Harshad number since it is a multiple of its sum of digits (42), and also a Moran number because the ratio is a prime number: 1578289 = 66288138 / (6 + 6 + 2 + 8 + 8 + 1 + 3 + 8).

It is a self number, because there is not a number n which added to its sum of digits gives 66288138.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 789103 + ... + 789186.

It is an arithmetic number, because the mean of its divisors is an integer number (9469740).

Almost surely, 2^66288138 is an apocalyptic number.

66288138 is an abundant number, since it is smaller than the sum of its proper divisors (85227702).

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

66288138 is a wasteful number, since it uses less digits than its factorization.

66288138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1578301.

The product of its digits is 110592, while the sum is 42.

The square root of 66288138 is about 8141.7527596949. The cubic root of 66288138 is about 404.7112466986.

The spelling of 66288138 in words is "sixty-six million, two hundred eighty-eight thousand, one hundred thirty-eight".