21432480 has 48 divisors (see below), whose sum is σ = 67513824. Its totient is φ = 5715200.

The previous prime is 21432473. The next prime is 21432493. The reversal of 21432480 is 8423412.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21432480.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21846 + ... + 22805.

It is an arithmetic number, because the mean of its divisors is an integer number (1406538).

Almost surely, 2^21432480 is an apocalyptic number.

21432480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21432480 is an abundant number, since it is smaller than the sum of its proper divisors (46081344).

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

21432480 is a wasteful number, since it uses less digits than its factorization.

21432480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44669 (or 44661 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 21432480 is about 4629.5226535789. The cubic root of 21432480 is about 277.7734987193.

Adding to 21432480 its reverse (8423412), we get a palindrome (29855892).

It can be divided in two parts, 21432 and 480, that added together give a palindrome (21912).

The spelling of 21432480 in words is "twenty-one million, four hundred thirty-two thousand, four hundred eighty".