216632441681 has 4 divisors (see below), whose sum is σ = 216676060992. Its totient is φ = 216588822372.

The previous prime is 216632441671. The next prime is 216632441687. The reversal of 216632441681 is 186144236612.

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 not a de Polignac number, because 216632441681 - 2²⁶ = 216565332817 is a prime.

It is a super-2 number, since 2×216632441681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216632441687) 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, 21802205 + ... + 21812138.

It is an arithmetic number, because the mean of its divisors is an integer number (54169015248).

Almost surely, 2^216632441681 is an apocalyptic number.

It is an amenable number.

216632441681 is a deficient number, since it is larger than the sum of its proper divisors (43619311).

216632441681 is an equidigital number, since it uses as much as digits as its factorization.

216632441681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43619310.

The product of its digits is 331776, while the sum is 44.

The spelling of 216632441681 in words is "two hundred sixteen billion, six hundred thirty-two million, four hundred forty-one thousand, six hundred eighty-one".