66947471839 has 4 divisors (see below), whose sum is σ = 67539927456. Its totient is φ = 66355016224.

The previous prime is 66947471827. The next prime is 66947471861. The reversal of 66947471839 is 93817474966.

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 66947471839 - 2¹¹ = 66947469791 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 (66947475839) 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, 296227639 + ... + 296227864.

It is an arithmetic number, because the mean of its divisors is an integer number (16884981864).

Almost surely, 2^66947471839 is an apocalyptic number.

66947471839 is a deficient number, since it is larger than the sum of its proper divisors (592455617).

66947471839 is a wasteful number, since it uses less digits than its factorization.

66947471839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592455616.

The product of its digits is 54867456, while the sum is 64.

The spelling of 66947471839 in words is "sixty-six billion, nine hundred forty-seven million, four hundred seventy-one thousand, eight hundred thirty-nine".