21494880 has 288 divisors, whose sum is σ = 84913920. Its totient is φ = 4899840.

The previous prime is 21494861. The next prime is 21494881. The reversal of 21494880 is 8849412.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21494881) 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 47 ways as a sum of consecutive naturals, for example, 364291 + ... + 364349.

It is an arithmetic number, because the mean of its divisors is an integer number (294840).

Almost surely, 2^21494880 is an apocalyptic number.

21494880 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 21494880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42456960).

21494880 is an abundant number, since it is smaller than the sum of its proper divisors (63419040).

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

21494880 is a wasteful number, since it uses less digits than its factorization.

21494880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114 (or 103 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 21494880 is about 4636.2571110757. The cubic root of 21494880 is about 278.0428138260.

The spelling of 21494880 in words is "twenty-one million, four hundred ninety-four thousand, eight hundred eighty".