11916021 has 24 divisors (see below), whose sum is σ = 18124320. Its totient is φ = 6941376.

The previous prime is 11916019. The next prime is 11916041. The reversal of 11916021 is 12061911.

It is not a de Polignac number, because 11916021 - 2¹ = 11916019 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11916041) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9015 + ... + 10251.

It is an arithmetic number, because the mean of its divisors is an integer number (755180).

Almost surely, 2^11916021 is an apocalyptic number.

It is an amenable number.

11916021 is a deficient number, since it is larger than the sum of its proper divisors (6208299).

11916021 is a wasteful number, since it uses less digits than its factorization.

11916021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1285 (or 1272 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 21.

The square root of 11916021 is about 3451.9590090266. The cubic root of 11916021 is about 228.4075313709.

Adding to 11916021 its reverse (12061911), we get a palindrome (23977932).

The spelling of 11916021 in words is "eleven million, nine hundred sixteen thousand, twenty-one".