21434213440 has 224 divisors, whose sum is σ = 54524574720. Its totient is φ = 8012390400.

The previous prime is 21434213407. The next prime is 21434213477. The reversal of 21434213440 is 4431243412.

It is a junction number, because it is equal to n+sod(n) for n = 21434213399 and 21434213408.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46494810 + ... + 46495270.

It is an arithmetic number, because the mean of its divisors is an integer number (243413280).

Almost surely, 2^21434213440 is an apocalyptic number.

21434213440 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 21434213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27262287360).

21434213440 is an abundant number, since it is smaller than the sum of its proper divisors (33090361280).

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

21434213440 is a wasteful number, since it uses less digits than its factorization.

21434213440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661 (or 651 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21434213440 its reverse (4431243412), we get a palindrome (25865456852).

The spelling of 21434213440 in words is "twenty-one billion, four hundred thirty-four million, two hundred thirteen thousand, four hundred forty".