16618261 has 6 divisors (see below), whose sum is σ = 18266486. Its totient is φ = 15107400.

The previous prime is 16618241. The next prime is 16618271. The reversal of 16618261 is 16281661.

It can be written as a sum of positive squares in only one way, i.e., 16564900 + 53361 = 4070^2 + 231^2 .

It is not a de Polignac number, because 16618261 - 2⁵ = 16618229 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 (16618241) 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, 68550 + ... + 68791.

Almost surely, 2^16618261 is an apocalyptic number.

16618261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16618261 is a deficient number, since it is larger than the sum of its proper divisors (1648225).

16618261 is a wasteful number, since it uses less digits than its factorization.

16618261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137363 (or 137352 counting only the distinct ones).

The product of its digits is 3456, while the sum is 31.

The square root of 16618261 is about 4076.5501346114. The cubic root of 16618261 is about 255.1889462117.

The spelling of 16618261 in words is "sixteen million, six hundred eighteen thousand, two hundred sixty-one".