66172350647 has 4 divisors (see below), whose sum is σ = 71262531480. Its totient is φ = 61082169816.

The previous prime is 66172350631. The next prime is 66172350653. The reversal of 66172350647 is 74605327166.

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

It is a cyclic number.

It is not a de Polignac number, because 66172350647 - 2⁴ = 66172350631 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66172350617) 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, 2545090397 + ... + 2545090422.

It is an arithmetic number, because the mean of its divisors is an integer number (17815632870).

Almost surely, 2^66172350647 is an apocalyptic number.

66172350647 is a deficient number, since it is larger than the sum of its proper divisors (5090180833).

66172350647 is a wasteful number, since it uses less digits than its factorization.

66172350647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5090180832.

The product of its (nonzero) digits is 1270080, while the sum is 47.

The spelling of 66172350647 in words is "sixty-six billion, one hundred seventy-two million, three hundred fifty thousand, six hundred forty-seven".