221636766465623 has 4 divisors (see below), whose sum is σ = 234674223316560. Its totient is φ = 208599309614688.

The previous prime is 221636766465607. The next prime is 221636766465629. The reversal of 221636766465623 is 326564667636122.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 221636766465623 - 2⁴ = 221636766465607 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221636766465623.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221636766465629) 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, 6518728425443 + ... + 6518728425476.

It is an arithmetic number, because the mean of its divisors is an integer number (58668555829140).

Almost surely, 2^{221636766465623} is an apocalyptic number.

221636766465623 is a deficient number, since it is larger than the sum of its proper divisors (13037456850937).

221636766465623 is a wasteful number, since it uses less digits than its factorization.

221636766465623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13037456850936.

The product of its digits is 470292480, while the sum is 65.

The spelling of 221636766465623 in words is "two hundred twenty-one trillion, six hundred thirty-six billion, seven hundred sixty-six million, four hundred sixty-five thousand, six hundred twenty-three".