11666538 has 32 divisors (see below), whose sum is σ = 27921600. Its totient is φ = 3589488.

The previous prime is 11666533. The next prime is 11666549. The reversal of 11666538 is 83566611.

It is a happy number.

It is a super-2 number, since 2×11666538² = 272216217810888, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11666533) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7608 + ... + 9011.

It is an arithmetic number, because the mean of its divisors is an integer number (872550).

Almost surely, 2^11666538 is an apocalyptic number.

11666538 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

11666538 is an abundant number, since it is smaller than the sum of its proper divisors (16255062).

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

11666538 is a wasteful number, since it uses less digits than its factorization.

11666538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16643 (or 16637 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 11666538 is about 3415.6314203965. The cubic root of 11666538 is about 226.8022367574.

The spelling of 11666538 in words is "eleven million, six hundred sixty-six thousand, five hundred thirty-eight".