216565635673 has 4 divisors (see below), whose sum is σ = 216571538560. Its totient is φ = 216559732788.

The previous prime is 216565635617. The next prime is 216565635743. The reversal of 216565635673 is 376536565612.

It is a happy number.

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-216565635673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216565635073) 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, 2896065 + ... + 2969902.

It is an arithmetic number, because the mean of its divisors is an integer number (54142884640).

Almost surely, 2^216565635673 is an apocalyptic number.

It is an amenable number.

216565635673 is a deficient number, since it is larger than the sum of its proper divisors (5902887).

216565635673 is an equidigital number, since it uses as much as digits as its factorization.

216565635673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5902886.

The product of its digits is 20412000, while the sum is 55.

The spelling of 216565635673 in words is "two hundred sixteen billion, five hundred sixty-five million, six hundred thirty-five thousand, six hundred seventy-three".