66621472884 has 108 divisors (see below), whose sum is σ = 172906607328. Its totient is φ = 21625702560.

The previous prime is 66621472877. The next prime is 66621472891. The reversal of 66621472884 is 48827412666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66621472877) and next prime (66621472891).

It is a self number, because there is not a number n which added to its sum of digits gives 66621472884.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15060297 + ... + 15064719.

Almost surely, 2^66621472884 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 66621472884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86453303664).

66621472884 is an abundant number, since it is smaller than the sum of its proper divisors (106285134444).

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

66621472884 is a wasteful number, since it uses less digits than its factorization.

66621472884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4658 (or 4582 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 54.

The spelling of 66621472884 in words is "sixty-six billion, six hundred twenty-one million, four hundred seventy-two thousand, eight hundred eighty-four".