66256801657 has 8 divisors (see below), whose sum is σ = 70835371776. Its totient is φ = 61753910592.

The previous prime is 66256801651. The next prime is 66256801669. The reversal of 66256801657 is 75610865266.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-66256801657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66256801651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18917953 + ... + 18921454.

It is an arithmetic number, because the mean of its divisors is an integer number (8854421472).

Almost surely, 2^66256801657 is an apocalyptic number.

It is an amenable number.

66256801657 is a deficient number, since it is larger than the sum of its proper divisors (4578570119).

66256801657 is a wasteful number, since it uses less digits than its factorization.

66256801657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37839527.

The product of its (nonzero) digits is 3628800, while the sum is 52.

The spelling of 66256801657 in words is "sixty-six billion, two hundred fifty-six million, eight hundred one thousand, six hundred fifty-seven".