66821112220 has 48 divisors (see below), whose sum is σ = 148612272480. Its totient is φ = 25150500864.

The previous prime is 66821112187. The next prime is 66821112233. The reversal of 66821112220 is 2221112866.

It is a super-2 number, since 2×66821112220² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1675876 + ... + 1715284.

It is an arithmetic number, because the mean of its divisors is an integer number (3096089010).

Almost surely, 2^66821112220 is an apocalyptic number.

It is an amenable number.

66821112220 is an abundant number, since it is smaller than the sum of its proper divisors (81791160260).

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

66821112220 is a wasteful number, since it uses less digits than its factorization.

66821112220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44422 (or 44420 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The spelling of 66821112220 in words is "sixty-six billion, eight hundred twenty-one million, one hundred twelve thousand, two hundred twenty".