11661556 has 12 divisors (see below), whose sum is σ = 20457892. Its totient is φ = 5816448.

The previous prime is 11661547. The next prime is 11661563. The reversal of 11661556 is 65516611.

It can be written as a sum of positive squares in 2 ways, for example, as 7376656 + 4284900 = 2716^2 + 2070^2 .

It is a super-2 number, since 2×11661556² = 271983776682272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1635 + ... + 5098.

Almost surely, 2^11661556 is an apocalyptic number.

It is an amenable number.

11661556 is a deficient number, since it is larger than the sum of its proper divisors (8796336).

11661556 is a wasteful number, since it uses less digits than its factorization.

11661556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7170 (or 7168 counting only the distinct ones).

The product of its digits is 5400, while the sum is 31.

The square root of 11661556 is about 3414.9020483756. The cubic root of 11661556 is about 226.7699481264.

The spelling of 11661556 in words is "eleven million, six hundred sixty-one thousand, five hundred fifty-six".