18661266 has 40 divisors (see below), whose sum is σ = 45036684. Its totient is φ = 5741280.

The previous prime is 18661259. The next prime is 18661271. The reversal of 18661266 is 66216681.

It can be written as a sum of positive squares in 2 ways, for example, as 18275625 + 385641 = 4275^2 + 621^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18661266.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2325 + ... + 6536.

Almost surely, 2^18661266 is an apocalyptic number.

18661266 is an abundant number, since it is smaller than the sum of its proper divisors (26375418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18661266 is a wasteful number, since it uses less digits than its factorization.

18661266 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8888 (or 8879 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 18661266 is about 4319.8687480061. The cubic root of 18661266 is about 265.2448952473.

The spelling of 18661266 in words is "eighteen million, six hundred sixty-one thousand, two hundred sixty-six".