66393984 has 64 divisors (see below), whose sum is σ = 181164240. Its totient is φ = 21528576.

The previous prime is 66393979. The next prime is 66393991. The reversal of 66393984 is 48939366.

66393984 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×66393984² = 8816322222784512, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 11872 + ... + 16544.

Almost surely, 2^66393984 is an apocalyptic number.

66393984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66393984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90582120).

66393984 is an abundant number, since it is smaller than the sum of its proper divisors (114770256).

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

66393984 is a wasteful number, since it uses less digits than its factorization.

66393984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4727 (or 4715 counting only the distinct ones).

The product of its digits is 839808, while the sum is 48.

The square root of 66393984 is about 8148.2503643420. The cubic root of 66393984 is about 404.9265405556.

The spelling of 66393984 in words is "sixty-six million, three hundred ninety-three thousand, nine hundred eighty-four".