21350442144 has 72 divisors (see below), whose sum is σ = 56566823040. Its totient is φ = 7051145472.

The previous prime is 21350442133. The next prime is 21350442161. The reversal of 21350442144 is 44124405312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1131217 + ... + 1149935.

It is an arithmetic number, because the mean of its divisors is an integer number (785650320).

Almost surely, 2^21350442144 is an apocalyptic number.

21350442144 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 21350442144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28283411520).

21350442144 is an abundant number, since it is smaller than the sum of its proper divisors (35216380896).

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

21350442144 is a wasteful number, since it uses less digits than its factorization.

21350442144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18950 (or 18833 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 30.

Adding to 21350442144 its reverse (44124405312), we get a palindrome (65474847456).

The spelling of 21350442144 in words is "twenty-one billion, three hundred fifty million, four hundred forty-two thousand, one hundred forty-four".