21418080 has 48 divisors (see below), whose sum is σ = 67468464. Its totient is φ = 5711360.

The previous prime is 21418069. The next prime is 21418087. The reversal of 21418080 is 8081412.

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 (24).

It is a self number, because there is not a number n which added to its sum of digits gives 21418080.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21418087) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21831 + ... + 22790.

It is an arithmetic number, because the mean of its divisors is an integer number (1405593).

Almost surely, 2^21418080 is an apocalyptic number.

21418080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21418080 is an abundant number, since it is smaller than the sum of its proper divisors (46050384).

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

21418080 is a wasteful number, since it uses less digits than its factorization.

21418080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44639 (or 44631 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 21418080 is about 4627.9671563225. The cubic root of 21418080 is about 277.7112748650.

Adding to 21418080 its reverse (8081412), we get a palindrome (29499492).

The spelling of 21418080 in words is "twenty-one million, four hundred eighteen thousand, eighty".