66165623657 has 8 divisors (see below), whose sum is σ = 75634151232. Its totient is φ = 56701170000.

The previous prime is 66165623639. The next prime is 66165623683. The reversal of 66165623657 is 75632656166.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 66165623657 - 2⁶ = 66165623593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66165623599 and 66165623608.

It is not an unprimeable number, because it can be changed into a prime (66165653657) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 983594 + ... + 1048707.

It is an arithmetic number, because the mean of its divisors is an integer number (9454268904).

Almost surely, 2^66165623657 is an apocalyptic number.

It is an amenable number.

66165623657 is a deficient number, since it is larger than the sum of its proper divisors (9468527575).

66165623657 is a wasteful number, since it uses less digits than its factorization.

66165623657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2036959.

The product of its digits is 8164800, while the sum is 53.

The spelling of 66165623657 in words is "sixty-six billion, one hundred sixty-five million, six hundred twenty-three thousand, six hundred fifty-seven".