216428231 has 4 divisors (see below), whose sum is σ = 216462000. Its totient is φ = 216394464.

The previous prime is 216428213. The next prime is 216428239. The reversal of 216428231 is 132824612.

It is a happy number.

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 216428231 - 2²⁶ = 149319367 is a prime.

It is a super-2 number, since 2×216428231² = 93682358347578722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 216428194 and 216428203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216428239) 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, 3986 + ... + 21183.

It is an arithmetic number, because the mean of its divisors is an integer number (54115500).

Almost surely, 2^216428231 is an apocalyptic number.

216428231 is a deficient number, since it is larger than the sum of its proper divisors (33769).

216428231 is an equidigital number, since it uses as much as digits as its factorization.

216428231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33768.

The product of its digits is 4608, while the sum is 29.

The square root of 216428231 is about 14711.4999575162. The cubic root of 216428231 is about 600.3962484395.

The spelling of 216428231 in words is "two hundred sixteen million, four hundred twenty-eight thousand, two hundred thirty-one".