21456480 has 48 divisors (see below), whose sum is σ = 67589424. Its totient is φ = 5721600.

The previous prime is 21456469. The next prime is 21456481. The reversal of 21456480 is 8465412.

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 (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21456481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21871 + ... + 22830.

It is an arithmetic number, because the mean of its divisors is an integer number (1408113).

Almost surely, 2^21456480 is an apocalyptic number.

21456480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21456480 is an abundant number, since it is smaller than the sum of its proper divisors (46132944).

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

21456480 is a wasteful number, since it uses less digits than its factorization.

21456480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44719 (or 44711 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 21456480 is about 4632.1139882347. The cubic root of 21456480 is about 277.8771432364.

The spelling of 21456480 in words is "twenty-one million, four hundred fifty-six thousand, four hundred eighty".