66977821504 has 112 divisors (see below), whose sum is σ = 152081544960. Its totient is φ = 28990863360.

The previous prime is 66977821429. The next prime is 66977821571. The reversal of 66977821504 is 40512877966.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1196902 + ... + 1251610.

Almost surely, 2^66977821504 is an apocalyptic number.

66977821504 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 66977821504, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76040772480).

66977821504 is an abundant number, since it is smaller than the sum of its proper divisors (85103723456).

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

66977821504 is a wasteful number, since it uses less digits than its factorization.

66977821504 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54816 (or 54806 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 55.

The spelling of 66977821504 in words is "sixty-six billion, nine hundred seventy-seven million, eight hundred twenty-one thousand, five hundred four".