66806814812 has 48 divisors (see below), whose sum is σ = 131594712480. Its totient is φ = 29488896000.

The previous prime is 66806814803. The next prime is 66806814817. The reversal of 66806814812 is 21841860866.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66806814817) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 125489 + ... + 386472.

It is an arithmetic number, because the mean of its divisors is an integer number (2741556510).

Almost surely, 2^66806814812 is an apocalyptic number.

It is an amenable number.

66806814812 is a deficient number, since it is larger than the sum of its proper divisors (64787897668).

66806814812 is a wasteful number, since it uses less digits than its factorization.

66806814812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512102 (or 512100 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 50.

The spelling of 66806814812 in words is "sixty-six billion, eight hundred six million, eight hundred fourteen thousand, eight hundred twelve".