66188557049 has 4 divisors (see below), whose sum is σ = 66189906036. Its totient is φ = 66187208064.

The previous prime is 66188557007. The next prime is 66188557051. The reversal of 66188557049 is 94075588166.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 25076939449 + 41111617600 = 158357^2 + 202760^2 .

It is a cyclic number.

It is not a de Polignac number, because 66188557049 - 2²⁸ = 65920121593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66188557069) 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, 598004 + ... + 699989.

It is an arithmetic number, because the mean of its divisors is an integer number (16547476509).

Almost surely, 2^66188557049 is an apocalyptic number.

It is an amenable number.

66188557049 is a deficient number, since it is larger than the sum of its proper divisors (1348987).

66188557049 is a wasteful number, since it uses less digits than its factorization.

66188557049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348986.

The product of its (nonzero) digits is 14515200, while the sum is 59.

The spelling of 66188557049 in words is "sixty-six billion, one hundred eighty-eight million, five hundred fifty-seven thousand, forty-nine".