21456120 has 192 divisors, whose sum is σ = 77565600. Its totient is φ = 4730880.

The previous prime is 21456107. The next prime is 21456131. The reversal of 21456120 is 2165412.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a zygodrome in base 9.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 241036 + ... + 241124.

Almost surely, 2^21456120 is an apocalyptic number.

21456120 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 21456120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38782800).

21456120 is an abundant number, since it is smaller than the sum of its proper divisors (56109480).

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

21456120 is a wasteful number, since it uses less digits than its factorization.

21456120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 21456120 is about 4632.0751289244. The cubic root of 21456120 is about 277.8755891397.

The spelling of 21456120 in words is "twenty-one million, four hundred fifty-six thousand, one hundred twenty".