66389838 has 32 divisors (see below), whose sum is σ = 142074240. Its totient is φ = 20619360.

The previous prime is 66389837. The next prime is 66389839. The reversal of 66389838 is 83898366.

It is an interprime number because it is at equal distance from previous prime (66389837) and next prime (66389839).

It is a super-2 number, since 2×66389838² = 8815221179332488, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66389837) 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, 2181 + ... + 11727.

It is an arithmetic number, because the mean of its divisors is an integer number (4439820).

Almost surely, 2^66389838 is an apocalyptic number.

66389838 is an abundant number, since it is smaller than the sum of its proper divisors (75684402).

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

66389838 is a wasteful number, since it uses less digits than its factorization.

66389838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9632.

The product of its digits is 1492992, while the sum is 51.

The square root of 66389838 is about 8147.9959499254. The cubic root of 66389838 is about 404.9181117780.

The spelling of 66389838 in words is "sixty-six million, three hundred eighty-nine thousand, eight hundred thirty-eight".