216642263 has 4 divisors (see below), whose sum is σ = 216695688. Its totient is φ = 216588840.

The previous prime is 216642247. The next prime is 216642281. The reversal of 216642263 is 362246612.

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 216642263 - 2⁴ = 216642247 is a prime.

It is a super-2 number, since 2×216642263² = 93867740235522338, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216642563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20081 + ... + 28922.

It is an arithmetic number, because the mean of its divisors is an integer number (54173922).

Almost surely, 2^216642263 is an apocalyptic number.

216642263 is a deficient number, since it is larger than the sum of its proper divisors (53425).

216642263 is an equidigital number, since it uses as much as digits as its factorization.

216642263 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53424.

The product of its digits is 20736, while the sum is 32.

The square root of 216642263 is about 14718.7724691973. The cubic root of 216642263 is about 600.5940995118.

Adding to 216642263 its reverse (362246612), we get a palindrome (578888875).

The spelling of 216642263 in words is "two hundred sixteen million, six hundred forty-two thousand, two hundred sixty-three".