66261142737697 has 4 divisors (see below), whose sum is σ = 66262916502676. Its totient is φ = 66259368972720.

The previous prime is 66261142737589. The next prime is 66261142737719. The reversal of 66261142737697 is 79673724116266.

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 32744499842961 + 33516642894736 = 5722281^2 + 5789356^2 .

It is a cyclic number.

It is not a de Polignac number, because 66261142737697 - 2³⁵ = 66226782999329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66261142731697) 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, 886826454 + ... + 886901167.

It is an arithmetic number, because the mean of its divisors is an integer number (16565729125669).

Almost surely, 2^{66261142737697} is an apocalyptic number.

It is an amenable number.

66261142737697 is a deficient number, since it is larger than the sum of its proper divisors (1773764979).

66261142737697 is a wasteful number, since it uses less digits than its factorization.

66261142737697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1773764978.

The product of its digits is 192036096, while the sum is 67.

The spelling of 66261142737697 in words is "sixty-six trillion, two hundred sixty-one billion, one hundred forty-two million, seven hundred thirty-seven thousand, six hundred ninety-seven".