21234144 has 48 divisors (see below), whose sum is σ = 55983312. Its totient is φ = 7047168.

The previous prime is 21234137. The next prime is 21234151. The reversal of 21234144 is 44143212.

It is an interprime number because it is at equal distance from previous prime (21234137) and next prime (21234151).

It is a tau number, because it is divible by the number of its divisors (48).

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 21234144.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 35512 + ... + 36104.

It is an arithmetic number, because the mean of its divisors is an integer number (1166319).

Almost surely, 2^21234144 is an apocalyptic number.

21234144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21234144 is an abundant number, since it is smaller than the sum of its proper divisors (34749168).

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

21234144 is a wasteful number, since it uses less digits than its factorization.

21234144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 979 (or 971 counting only the distinct ones).

The product of its digits is 768, while the sum is 21.

The square root of 21234144 is about 4608.0520830390. The cubic root of 21234144 is about 276.9140040712.

Adding to 21234144 its reverse (44143212), we get a palindrome (65377356).

The spelling of 21234144 in words is "twenty-one million, two hundred thirty-four thousand, one hundred forty-four".