66284215920 has 320 divisors, whose sum is σ = 247824138240. Its totient is φ = 16186770432.

The previous prime is 66284215901. The next prime is 66284215973. The reversal of 66284215920 is 2951248266.

66284215920 is a `hidden beast` number, since 6 + 628 + 4 + 2 + 15 + 9 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3556867 + ... + 3575453.

It is an arithmetic number, because the mean of its divisors is an integer number (774450432).

Almost surely, 2^66284215920 is an apocalyptic number.

66284215920 is a gapful number since it is divisible by the number (60) 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 66284215920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123912069120).

66284215920 is an abundant number, since it is smaller than the sum of its proper divisors (181539922320).

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

66284215920 is a wasteful number, since it uses less digits than its factorization.

66284215920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18749 (or 18737 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 66284215920 in words is "sixty-six billion, two hundred eighty-four million, two hundred fifteen thousand, nine hundred twenty".