21043480 has 16 divisors (see below), whose sum is σ = 47347920. Its totient is φ = 8417376.

The previous prime is 21043457. The next prime is 21043481. The reversal of 21043480 is 8434012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21043481) 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, 263004 + ... + 263083.

It is an arithmetic number, because the mean of its divisors is an integer number (2959245).

Almost surely, 2^21043480 is an apocalyptic number.

21043480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21043480 is an abundant number, since it is smaller than the sum of its proper divisors (26304440).

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

21043480 is a wasteful number, since it uses less digits than its factorization.

21043480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 526098 (or 526094 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21043480 is about 4587.3172988142. The cubic root of 21043480 is about 276.0826959369.

Adding to 21043480 its reverse (8434012), we get a palindrome (29477492).

The spelling of 21043480 in words is "twenty-one million, forty-three thousand, four hundred eighty".