66131257705 has 8 divisors (see below), whose sum is σ = 81293058504. Its totient is φ = 51614640000.

The previous prime is 66131257667. The next prime is 66131257721. The reversal of 66131257705 is 50775213166.

It can be written as a sum of positive squares in 4 ways, for example, as 555827776 + 65575429929 = 23576^2 + 256077^2 .

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-66131257705 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161295546 + ... + 161295955.

It is an arithmetic number, because the mean of its divisors is an integer number (10161632313).

Almost surely, 2^66131257705 is an apocalyptic number.

It is an amenable number.

66131257705 is a deficient number, since it is larger than the sum of its proper divisors (15161800799).

66131257705 is a wasteful number, since it uses less digits than its factorization.

66131257705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322591547.

The product of its (nonzero) digits is 264600, while the sum is 43.

The spelling of 66131257705 in words is "sixty-six billion, one hundred thirty-one million, two hundred fifty-seven thousand, seven hundred five".