21851124 has 12 divisors (see below), whose sum is σ = 50985984. Its totient is φ = 7283704.

The previous prime is 21851119. The next prime is 21851153. The reversal of 21851124 is 42115812.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21851094 and 21851103.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 910452 + ... + 910475.

It is an arithmetic number, because the mean of its divisors is an integer number (4248832).

Almost surely, 2^21851124 is an apocalyptic number.

It is an amenable number.

21851124 is an abundant number, since it is smaller than the sum of its proper divisors (29134860).

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

21851124 is a wasteful number, since it uses less digits than its factorization.

21851124 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1820934 (or 1820932 counting only the distinct ones).

The product of its digits is 640, while the sum is 24.

The square root of 21851124 is about 4674.5185848384. The cubic root of 21851124 is about 279.5704467936.

Adding to 21851124 its reverse (42115812), we get a palindrome (63966936).

The spelling of 21851124 in words is "twenty-one million, eight hundred fifty-one thousand, one hundred twenty-four".