21411264 has 112 divisors (see below), whose sum is σ = 65836800. Its totient is φ = 6014976.

The previous prime is 21411263. The next prime is 21411281. The reversal of 21411264 is 46211412.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 21411264.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21411263) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 119527 + ... + 119705.

Almost surely, 2^21411264 is an apocalyptic number.

21411264 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 21411264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32918400).

21411264 is an abundant number, since it is smaller than the sum of its proper divisors (44425536).

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

21411264 is a wasteful number, since it uses less digits than its factorization.

21411264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 290 (or 280 counting only the distinct ones).

The product of its digits is 384, while the sum is 21.

The square root of 21411264 is about 4627.2307052923. The cubic root of 21411264 is about 277.6818125154.

Adding to 21411264 its reverse (46211412), we get a palindrome (67622676).

The spelling of 21411264 in words is "twenty-one million, four hundred eleven thousand, two hundred sixty-four".