21102480 has 240 divisors, whose sum is σ = 83566080. Its totient is φ = 4672512.

The previous prime is 21102467. The next prime is 21102481. The reversal of 21102480 is 8420112.

It is a tau number, because it is divible by the number of its divisors (240).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21102481) 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, 267081 + ... + 267159.

It is an arithmetic number, because the mean of its divisors is an integer number (348192).

Almost surely, 2^21102480 is an apocalyptic number.

21102480 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 21102480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41783040).

21102480 is an abundant number, since it is smaller than the sum of its proper divisors (62463600).

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

21102480 is a wasteful number, since it uses less digits than its factorization.

21102480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 21102480 is about 4593.7435714241. The cubic root of 21102480 is about 276.3404745866.

Adding to 21102480 its reverse (8420112), we get a palindrome (29522592).

The spelling of 21102480 in words is "twenty-one million, one hundred two thousand, four hundred eighty".