21043450 has 48 divisors (see below), whose sum is σ = 43657920. Its totient is φ = 7499520.

The previous prime is 21043441. The next prime is 21043453. The reversal of 21043450 is 5434012.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (21043453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15499 + ... + 16801.

It is an arithmetic number, because the mean of its divisors is an integer number (909540).

Almost surely, 2^21043450 is an apocalyptic number.

21043450 is an abundant number, since it is smaller than the sum of its proper divisors (22614470).

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

21043450 is a wasteful number, since it uses less digits than its factorization.

21043450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1351 (or 1346 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21043450 is about 4587.3140289280. The cubic root of 21043450 is about 276.0825647405.

Adding to 21043450 its reverse (5434012), we get a palindrome (26477462).

It can be divided in two parts, 210 and 43450, that added together give a triangular number (43660 = T₂₉₅).

The spelling of 21043450 in words is "twenty-one million, forty-three thousand, four hundred fifty".