66391416 has 96 divisors (see below), whose sum is σ = 221326560. Its totient is φ = 17508096.

The previous prime is 66391399. The next prime is 66391417. The reversal of 66391416 is 61419366.

66391416 is a `hidden beast` number, since 6 + 639 + 1 + 4 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66391417) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1486 + ... + 11618.

It is an arithmetic number, because the mean of its divisors is an integer number (2305485).

Almost surely, 2^66391416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66391416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110663280).

66391416 is an abundant number, since it is smaller than the sum of its proper divisors (154935144).

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

66391416 is a wasteful number, since it uses less digits than its factorization.

66391416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10165 (or 10158 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 66391416 is about 8148.0927829769. The cubic root of 66391416 is about 404.9213198780.

The spelling of 66391416 in words is "sixty-six million, three hundred ninety-one thousand, four hundred sixteen".