66755393447 has 4 divisors (see below), whose sum is σ = 66901466976. Its totient is φ = 66609319920.

The previous prime is 66755393437. The next prime is 66755393483. The reversal of 66755393447 is 74439355766.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66755393447 - 2²⁶ = 66688284583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66755393437) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 73036079 + ... + 73036992.

It is an arithmetic number, because the mean of its divisors is an integer number (16725366744).

Almost surely, 2^66755393447 is an apocalyptic number.

66755393447 is a deficient number, since it is larger than the sum of its proper divisors (146073529).

66755393447 is a wasteful number, since it uses less digits than its factorization.

66755393447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146073528.

The product of its digits is 57153600, while the sum is 59.

The spelling of 66755393447 in words is "sixty-six billion, seven hundred fifty-five million, three hundred ninety-three thousand, four hundred forty-seven".