21121116 has 24 divisors (see below), whose sum is σ = 49674240. Its totient is φ = 6984432.

The previous prime is 21121099. The next prime is 21121129. The reversal of 21121116 is 61112112.

It is a happy number.

It is a super-2 number, since 2×21121116² = 892203082170912, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21121095 and 21121104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5406 + ... + 8453.

It is an arithmetic number, because the mean of its divisors is an integer number (2069760).

Almost surely, 2^21121116 is an apocalyptic number.

It is an amenable number.

21121116 is an abundant number, since it is smaller than the sum of its proper divisors (28553124).

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

21121116 is a wasteful number, since it uses less digits than its factorization.

21121116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13993 (or 13991 counting only the distinct ones).

The product of its digits is 24, while the sum is 15.

The square root of 21121116 is about 4595.7715347915. The cubic root of 21121116 is about 276.4217978220.

Adding to 21121116 its reverse (61112112), we get a palindrome (82233228).

The spelling of 21121116 in words is "twenty-one million, one hundred twenty-one thousand, one hundred sixteen".