21438850395508 has 648 divisors, whose sum is σ = 51743479525920. Its totient is φ = 7722751196160.

The previous prime is 21438850395499. The next prime is 21438850395511. The reversal of 21438850395508 is 80559305883412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 118446687178 + ... + 118446687358.

Almost surely, 2^{21438850395508} is an apocalyptic number.

21438850395508 is a gapful number since it is divisible by the number (28) 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 21438850395508, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25871739762960).

21438850395508 is an abundant number, since it is smaller than the sum of its proper divisors (30304629130412).

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

21438850395508 is a wasteful number, since it uses less digits than its factorization.

21438850395508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 417 (or 342 counting only the distinct ones).

The product of its (nonzero) digits is 41472000, while the sum is 61.

The spelling of 21438850395508 in words is "twenty-one trillion, four hundred thirty-eight billion, eight hundred fifty million, three hundred ninety-five thousand, five hundred eight".