21641231304 has 192 divisors, whose sum is σ = 73610259840. Its totient is φ = 5579873280.

The previous prime is 21641231281. The next prime is 21641231321. The reversal of 21641231304 is 40313214612.

It is a happy number.

21641231304 is a `hidden beast` number, since 2 + 1 + 641 + 2 + 3 + 13 + 0 + 4 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 745282 + ... + 773774.

It is an arithmetic number, because the mean of its divisors is an integer number (383386770).

Almost surely, 2^21641231304 is an apocalyptic number.

21641231304 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 21641231304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36805129920).

21641231304 is an abundant number, since it is smaller than the sum of its proper divisors (51969028536).

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

21641231304 is a wasteful number, since it uses less digits than its factorization.

21641231304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28660 (or 28653 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

Adding to 21641231304 its reverse (40313214612), we get a palindrome (61954445916).

The spelling of 21641231304 in words is "twenty-one billion, six hundred forty-one million, two hundred thirty-one thousand, three hundred four".