21121168 has 40 divisors (see below), whose sum is σ = 42775040. Its totient is φ = 10091520.

The previous prime is 21121129. The next prime is 21121171. The reversal of 21121168 is 86112112.

It is a super-2 number, since 2×21121168² = 892207475368448, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47893 + ... + 48331.

It is an arithmetic number, because the mean of its divisors is an integer number (1069376).

Almost surely, 2^21121168 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21387520).

21121168 is an abundant number, since it is smaller than the sum of its proper divisors (21653872).

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

21121168 is a wasteful number, since it uses less digits than its factorization.

21121168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575 (or 569 counting only the distinct ones).

The product of its digits is 192, while the sum is 22.

The square root of 21121168 is about 4595.7771921624. Note that the first 3 decimals coincide. The cubic root of 21121168 is about 276.4220246711.

The spelling of 21121168 in words is "twenty-one million, one hundred twenty-one thousand, one hundred sixty-eight".