66642665441 has 4 divisors (see below), whose sum is σ = 72701089584. Its totient is φ = 60584241300.

The previous prime is 66642665437. The next prime is 66642665449. The reversal of 66642665441 is 14456624666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 66642665441 - 2² = 66642665437 is a prime.

It is a Duffinian number.

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 66642665441.

It is not an unprimeable number, because it can be changed into a prime (66642665449) 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, 3029212055 + ... + 3029212076.

It is an arithmetic number, because the mean of its divisors is an integer number (18175272396).

Almost surely, 2^66642665441 is an apocalyptic number.

It is an amenable number.

66642665441 is a deficient number, since it is larger than the sum of its proper divisors (6058424143).

66642665441 is a wasteful number, since it uses less digits than its factorization.

66642665441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6058424142.

The product of its digits is 4976640, while the sum is 50.

The spelling of 66642665441 in words is "sixty-six billion, six hundred forty-two million, six hundred sixty-five thousand, four hundred forty-one".