21400480 has 48 divisors (see below), whose sum is σ = 51438240. Its totient is φ = 8411392.

The previous prime is 21400459. The next prime is 21400487. The reversal of 21400480 is 8400412.

It is not an unprimeable number, because it can be changed into a prime (21400487) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8307 + ... + 10573.

It is an arithmetic number, because the mean of its divisors is an integer number (1071630).

Almost surely, 2^21400480 is an apocalyptic number.

21400480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21400480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25719120).

21400480 is an abundant number, since it is smaller than the sum of its proper divisors (30037760).

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

21400480 is a wasteful number, since it uses less digits than its factorization.

21400480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2341 (or 2333 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 21400480 is about 4626.0652827214. The cubic root of 21400480 is about 277.6351856006.

Adding to 21400480 its reverse (8400412), we get a palindrome (29800892).

The spelling of 21400480 in words is "twenty-one million, four hundred thousand, four hundred eighty".