66201623861 has 4 divisors (see below), whose sum is σ = 66216316992. Its totient is φ = 66186930732.

The previous prime is 66201623783. The next prime is 66201623869. The reversal of 66201623861 is 16832610266.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66201623861 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 (66201623869) 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, 7339805 + ... + 7348818.

It is an arithmetic number, because the mean of its divisors is an integer number (16554079248).

Almost surely, 2^66201623861 is an apocalyptic number.

It is an amenable number.

66201623861 is a deficient number, since it is larger than the sum of its proper divisors (14693131).

66201623861 is a wasteful number, since it uses less digits than its factorization.

66201623861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14693130.

The product of its (nonzero) digits is 124416, while the sum is 41.

The spelling of 66201623861 in words is "sixty-six billion, two hundred one million, six hundred twenty-three thousand, eight hundred sixty-one".