66787549169 has 4 divisors (see below), whose sum is σ = 72859144560. Its totient is φ = 60715953780.

The previous prime is 66787549151. The next prime is 66787549177. The reversal of 66787549169 is 96194578766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66787549169 is a prime.

It is a super-2 number, since 2×66787549169² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66787549099 and 66787549108.

It is not an unprimeable number, because it can be changed into a prime (66787549369) 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, 3035797679 + ... + 3035797700.

It is an arithmetic number, because the mean of its divisors is an integer number (18214786140).

Almost surely, 2^66787549169 is an apocalyptic number.

It is an amenable number.

66787549169 is a deficient number, since it is larger than the sum of its proper divisors (6071595391).

66787549169 is a wasteful number, since it uses less digits than its factorization.

66787549169 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6071595390.

The product of its digits is 137168640, while the sum is 68.

The spelling of 66787549169 in words is "sixty-six billion, seven hundred eighty-seven million, five hundred forty-nine thousand, one hundred sixty-nine".