66201623865 has 96 divisors (see below), whose sum is σ = 127602708480. Its totient is φ = 32550336000.

The previous prime is 66201623783. The next prime is 66201623869. The reversal of 66201623865 is 56832610266.

66201623865 is a `hidden beast` number, since 6 + 6 + 201 + 62 + 386 + 5 = 666.

It is not a de Polignac number, because 66201623865 - 2²⁰ = 66200575289 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66201623865.

It is not an unprimeable number, because it can be changed into a prime (66201623869) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 26258805 + ... + 26261325.

It is an arithmetic number, because the mean of its divisors is an integer number (1329194880).

Almost surely, 2^66201623865 is an apocalyptic number.

66201623865 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66201623865 is a deficient number, since it is larger than the sum of its proper divisors (61401084615).

66201623865 is a wasteful number, since it uses less digits than its factorization.

66201623865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3712 (or 3693 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 45.

The spelling of 66201623865 in words is "sixty-six billion, two hundred one million, six hundred twenty-three thousand, eight hundred sixty-five".