21120264 has 80 divisors (see below), whose sum is σ = 64555920. Its totient is φ = 6397920.

The previous prime is 21120259. The next prime is 21120271. The reversal of 21120264 is 46202112.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 5647 + ... + 8609.

It is an arithmetic number, because the mean of its divisors is an integer number (806949).

Almost surely, 2^21120264 is an apocalyptic number.

21120264 is a gapful number since it is divisible by the number (24) 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 21120264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32277960).

21120264 is an abundant number, since it is smaller than the sum of its proper divisors (43435656).

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

21120264 is a wasteful number, since it uses less digits than its factorization.

21120264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2992 (or 2979 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21120264 is about 4595.6788399539. The cubic root of 21120264 is about 276.4180809329.

Adding to 21120264 its reverse (46202112), we get a palindrome (67322376).

The spelling of 21120264 in words is "twenty-one million, one hundred twenty thousand, two hundred sixty-four".