21352044672 has 192 divisors, whose sum is σ = 70776576000. Its totient is φ = 6052257792.

The previous prime is 21352044631. The next prime is 21352044673. The reversal of 21352044672 is 27644025312.

21352044672 is a `hidden beast` number, since 21 + 3 + 520 + 4 + 46 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21352044673) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1013704 + ... + 1034552.

It is an arithmetic number, because the mean of its divisors is an integer number (368628000).

Almost surely, 2^21352044672 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21352044672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35388288000).

21352044672 is an abundant number, since it is smaller than the sum of its proper divisors (49424531328).

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

21352044672 is a wasteful number, since it uses less digits than its factorization.

21352044672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21003 (or 20988 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 36.

Adding to 21352044672 its product of nonzero digits (80640), we get a palindrome (21352125312).

Adding to 21352044672 its reverse (27644025312), we get a palindrome (48996069984).

The spelling of 21352044672 in words is "twenty-one billion, three hundred fifty-two million, forty-four thousand, six hundred seventy-two".