66709543309956 has 36 divisors (see below), whose sum is σ = 168733694766000. Its totient is φ = 22222431761328.

The previous prime is 66709543309939. The next prime is 66709543309967. The reversal of 66709543309956 is 65990334590766.

66709543309956 is a `hidden beast` number, since 6 + 6 + 70 + 9 + 543 + 3 + 0 + 9 + 9 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

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 11 ways as a sum of consecutive naturals, for example, 586720506 + ... + 586834193.

Almost surely, 2^{66709543309956} is an apocalyptic number.

It is an amenable number.

66709543309956 is an abundant number, since it is smaller than the sum of its proper divisors (102024151456044).

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

66709543309956 is a wasteful number, since it uses less digits than its factorization.

66709543309956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173556288 (or 1173556283 counting only the distinct ones).

The product of its (nonzero) digits is 992023200, while the sum is 72.

The spelling of 66709543309956 in words is "sixty-six trillion, seven hundred nine billion, five hundred forty-three million, three hundred nine thousand, nine hundred fifty-six".