21480420 has 48 divisors (see below), whose sum is σ = 64774080. Its totient is φ = 5287296.

The previous prime is 21480397. The next prime is 21480439. The reversal of 21480420 is 2408412.

It is a super-2 number, since 2×21480420² = 922816886752800, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12990 + ... + 14549.

It is an arithmetic number, because the mean of its divisors is an integer number (1349460).

Almost surely, 2^21480420 is an apocalyptic number.

21480420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21480420 is an abundant number, since it is smaller than the sum of its proper divisors (43293660).

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

21480420 is a wasteful number, since it uses less digits than its factorization.

21480420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27564 (or 27562 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

The square root of 21480420 is about 4634.6974011256. The cubic root of 21480420 is about 277.9804516731.

Adding to 21480420 its reverse (2408412), we get a palindrome (23888832).

The spelling of 21480420 in words is "twenty-one million, four hundred eighty thousand, four hundred twenty".