21442680 has 192 divisors, whose sum is σ = 81469440. Its totient is φ = 4790016.

The previous prime is 21442667. The next prime is 21442699. The reversal of 21442680 is 8624412.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 168777 + ... + 168903.

It is an arithmetic number, because the mean of its divisors is an integer number (424320).

Almost surely, 2^21442680 is an apocalyptic number.

21442680 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 21442680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40734720).

21442680 is an abundant number, since it is smaller than the sum of its proper divisors (60026760).

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

21442680 is a wasteful number, since it uses less digits than its factorization.

21442680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 211 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 21442680 is about 4630.6241479956. The cubic root of 21442680 is about 277.8175570883.

It can be divided in two parts, 21442 and 680, that added together give a palindrome (22122).

The spelling of 21442680 in words is "twenty-one million, four hundred forty-two thousand, six hundred eighty".