21121443 has 12 divisors (see below), whose sum is σ = 34867248. Its totient is φ = 12069360.

The previous prime is 21121417. The next prime is 21121453. The reversal of 21121443 is 34412112.

It is not a de Polignac number, because 21121443 - 2⁵ = 21121411 is a prime.

It is a super-2 number, since 2×21121443² = 892230708804498, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 167568 + ... + 167693.

It is an arithmetic number, because the mean of its divisors is an integer number (2905604).

Almost surely, 2^21121443 is an apocalyptic number.

21121443 is a deficient number, since it is larger than the sum of its proper divisors (13745805).

21121443 is a wasteful number, since it uses less digits than its factorization.

21121443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335274 (or 335271 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 21121443 is about 4595.8071108348. The cubic root of 21121443 is about 276.4232243479.

Adding to 21121443 its reverse (34412112), we get a palindrome (55533555).

The spelling of 21121443 in words is "twenty-one million, one hundred twenty-one thousand, four hundred forty-three".