16218261 has 6 divisors (see below), whose sum is σ = 23426390. Its totient is φ = 10812168.

The previous prime is 16218259. The next prime is 16218263. The reversal of 16218261 is 16281261.

It is an interprime number because it is at equal distance from previous prime (16218259) and next prime (16218263).

It can be written as a sum of positive squares in only one way, i.e., 13950225 + 2268036 = 3735^2 + 1506^2 .

It is not a de Polignac number, because 16218261 - 2¹ = 16218259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16218263) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 901006 + ... + 901023.

Almost surely, 2^16218261 is an apocalyptic number.

It is an amenable number.

16218261 is a deficient number, since it is larger than the sum of its proper divisors (7208129).

16218261 is a wasteful number, since it uses less digits than its factorization.

16218261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1802035 (or 1802032 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 16218261 is about 4027.1902115495. The cubic root of 16218261 is about 253.1248374942.

The spelling of 16218261 in words is "sixteen million, two hundred eighteen thousand, two hundred sixty-one".