66572671765 has 4 divisors (see below), whose sum is σ = 79887206124. Its totient is φ = 53258137408.

The previous prime is 66572671699. The next prime is 66572671777. The reversal of 66572671765 is 56717627566.

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 29807677201 + 36764994564 = 172649^2 + 191742^2 .

It is a cyclic number.

It is not a de Polignac number, because 66572671765 - 2²³ = 66564283157 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6657267172 + ... + 6657267181.

It is an arithmetic number, because the mean of its divisors is an integer number (19971801531).

Almost surely, 2^66572671765 is an apocalyptic number.

It is an amenable number.

66572671765 is a deficient number, since it is larger than the sum of its proper divisors (13314534359).

66572671765 is a wasteful number, since it uses less digits than its factorization.

66572671765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13314534358.

The product of its digits is 22226400, while the sum is 58.

The spelling of 66572671765 in words is "sixty-six billion, five hundred seventy-two million, six hundred seventy-one thousand, seven hundred sixty-five".