21043752 has 16 divisors (see below), whose sum is σ = 52609440. Its totient is φ = 7014576.

The previous prime is 21043747. The next prime is 21043753. The reversal of 21043752 is 25734012.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 876823 = 21043752 / (2 + 1 + 0 + 4 + 3 + 7 + 5 + 2).

It is not an unprimeable number, because it can be changed into a prime (21043753) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 438388 + ... + 438435.

It is an arithmetic number, because the mean of its divisors is an integer number (3288090).

Almost surely, 2^21043752 is an apocalyptic number.

It is an amenable number.

21043752 is an abundant number, since it is smaller than the sum of its proper divisors (31565688).

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

21043752 is a wasteful number, since it uses less digits than its factorization.

21043752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876832 (or 876828 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 21043752 is about 4587.3469456757. The cubic root of 21043752 is about 276.0838854450.

Adding to 21043752 its reverse (25734012), we get a palindrome (46777764).

The spelling of 21043752 in words is "twenty-one million, forty-three thousand, seven hundred fifty-two".