21239742433560 has 256 divisors, whose sum is σ = 74401962393600. Its totient is φ = 4749550689792.

The previous prime is 21239742433549. The next prime is 21239742433589. The reversal of 21239742433560 is 6533424793212.

It is a happy number.

It is a super-2 number, since 2×21239742433560² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 96971929 + ... + 97190711.

It is an arithmetic number, because the mean of its divisors is an integer number (290632665600).

Almost surely, 2^{21239742433560} is an apocalyptic number.

21239742433560 is a gapful number since it is divisible by the number (20) 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 21239742433560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37200981196800).

21239742433560 is an abundant number, since it is smaller than the sum of its proper divisors (53162219960040).

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

21239742433560 is a wasteful number, since it uses less digits than its factorization.

21239742433560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221310 (or 221306 counting only the distinct ones).

The product of its (nonzero) digits is 6531840, while the sum is 51.

The spelling of 21239742433560 in words is "twenty-one trillion, two hundred thirty-nine billion, seven hundred forty-two million, four hundred thirty-three thousand, five hundred sixty".