216144261 has 8 divisors (see below), whose sum is σ = 320213760. Its totient is φ = 144096156.

The previous prime is 216144233. The next prime is 216144281. The reversal of 216144261 is 162441612.

216144261 is a `hidden beast` number, since 2 + 1 + 614 + 42 + 6 + 1 = 666.

It is not a de Polignac number, because 216144261 - 2⁶ = 216144197 is a prime.

It is a super-2 number, since 2×216144261² = 93436683126472242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 8005343 = 216144261 / (2 + 1 + 6 + 1 + 4 + 4 + 2 + 6 + 1).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216144281) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4002645 + ... + 4002698.

It is an arithmetic number, because the mean of its divisors is an integer number (40026720).

Almost surely, 2^216144261 is an apocalyptic number.

It is an amenable number.

216144261 is a deficient number, since it is larger than the sum of its proper divisors (104069499).

216144261 is an equidigital number, since it uses as much as digits as its factorization.

216144261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8005352 (or 8005346 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 216144261 is about 14701.8454963994. The cubic root of 216144261 is about 600.1335452739.

Adding to 216144261 its reverse (162441612), we get a palindrome (378585873).

The spelling of 216144261 in words is "two hundred sixteen million, one hundred forty-four thousand, two hundred sixty-one".