21439236169728 has 896 divisors, whose sum is σ = 69513200064000. Its totient is φ = 6491003682816.

The previous prime is 21439236169721. The next prime is 21439236169739. The reversal of 21439236169728 is 82796163293412.

21439236169728 is a `hidden beast` number, since 2 + 1 + 4 + 3 + 9 + 2 + 3 + 616 + 9 + 7 + 2 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21439236169721) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 69834645351 + ... + 69834645657.

It is an arithmetic number, because the mean of its divisors is an integer number (77581696500).

Almost surely, 2^{21439236169728} 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 21439236169728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34756600032000).

21439236169728 is an abundant number, since it is smaller than the sum of its proper divisors (48073963894272).

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

21439236169728 is a wasteful number, since it uses less digits than its factorization.

21439236169728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667 (or 637 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 63.

The spelling of 21439236169728 in words is "twenty-one trillion, four hundred thirty-nine billion, two hundred thirty-six million, one hundred sixty-nine thousand, seven hundred twenty-eight".