66687138 has 120 divisors (see below), whose sum is σ = 180094464. Its totient is φ = 18370800.

The previous prime is 66687121. The next prime is 66687151. The reversal of 66687138 is 83178666.

66687138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 66687093 and 66687102.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 245943 + ... + 246213.

Almost surely, 2^66687138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66687138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90047232).

66687138 is an abundant number, since it is smaller than the sum of its proper divisors (113407326).

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

66687138 is a wasteful number, since it uses less digits than its factorization.

66687138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 314 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 66687138 is about 8166.2193210812. The cubic root of 66687138 is about 405.5216323856.

The spelling of 66687138 in words is "sixty-six million, six hundred eighty-seven thousand, one hundred thirty-eight".