66138648 has 32 divisors (see below), whose sum is σ = 167818560. Its totient is φ = 21716640.

The previous prime is 66138637. The next prime is 66138661. The reversal of 66138648 is 84683166.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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, 18958 + ... + 22173.

It is an arithmetic number, because the mean of its divisors is an integer number (5244330).

Almost surely, 2^66138648 is an apocalyptic number.

It is an amenable number.

66138648 is an abundant number, since it is smaller than the sum of its proper divisors (101679912).

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

66138648 is a wasteful number, since it uses less digits than its factorization.

66138648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41207 (or 41203 counting only the distinct ones).

The product of its digits is 165888, while the sum is 42.

The square root of 66138648 is about 8132.5671223790. The cubic root of 66138648 is about 404.4067889061.

The spelling of 66138648 in words is "sixty-six million, one hundred thirty-eight thousand, six hundred forty-eight".