21427120 has 80 divisors (see below), whose sum is σ = 58558752. Its totient is φ = 7188480.

The previous prime is 21427103. The next prime is 21427121. The reversal of 21427120 is 2172412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21427121) by changing a digit.

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, 10504 + ... + 12376.

Almost surely, 2^21427120 is an apocalyptic number.

21427120 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 21427120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29279376).

21427120 is an abundant number, since it is smaller than the sum of its proper divisors (37131632).

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

21427120 is a wasteful number, since it uses less digits than its factorization.

21427120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1910 (or 1904 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21427120 is about 4628.9437240044. The cubic root of 21427120 is about 277.7503408753.

Adding to 21427120 its reverse (2172412), we get a palindrome (23599532).

The spelling of 21427120 in words is "twenty-one million, four hundred twenty-seven thousand, one hundred twenty".