66811520338747 has 8 divisors (see below), whose sum is σ = 70769039677200. Its totient is φ = 62857048767744.

The previous prime is 66811520338669. The next prime is 66811520338777. The reversal of 66811520338747 is 74783302511866.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66811520338747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66811520338777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 761896722 + ... + 761984407.

It is an arithmetic number, because the mean of its divisors is an integer number (8846129959650).

Almost surely, 2^{66811520338747} is an apocalyptic number.

66811520338747 is a deficient number, since it is larger than the sum of its proper divisors (3957519338453).

66811520338747 is a wasteful number, since it uses less digits than its factorization.

66811520338747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1523883725.

The product of its (nonzero) digits is 40642560, while the sum is 61.

The spelling of 66811520338747 in words is "sixty-six trillion, eight hundred eleven billion, five hundred twenty million, three hundred thirty-eight thousand, seven hundred forty-seven".