66663648 has 72 divisors (see below), whose sum is σ = 196618968. Its totient is φ = 22218624.

The previous prime is 66663617. The next prime is 66663659. The reversal of 66663648 is 84636666.

It is a tau number, because it is divible by the number of its divisors (72).

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 11 ways as a sum of consecutive naturals, for example, 3490 + ... + 12062.

It is an arithmetic number, because the mean of its divisors is an integer number (2730819).

Almost surely, 2^66663648 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 66663648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98309484).

66663648 is an abundant number, since it is smaller than the sum of its proper divisors (129955320).

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

66663648 is an equidigital number, since it uses as much as digits as its factorization.

66663648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8598 (or 8578 counting only the distinct ones).

The product of its digits is 746496, while the sum is 45.

The square root of 66663648 is about 8164.7809523587. The cubic root of 66663648 is about 405.4740128990.

The spelling of 66663648 in words is "sixty-six million, six hundred sixty-three thousand, six hundred forty-eight".