21453505440 has 192 divisors, whose sum is σ = 68802048000. Its totient is φ = 5618156544.

The previous prime is 21453505439. The next prime is 21453505481. The reversal of 21453505440 is 4450535412.

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, 7544659 + ... + 7547501.

It is an arithmetic number, because the mean of its divisors is an integer number (358344000).

Almost surely, 2^21453505440 is an apocalyptic number.

21453505440 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 21453505440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34401024000).

21453505440 is an abundant number, since it is smaller than the sum of its proper divisors (47348542560).

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

21453505440 is a wasteful number, since it uses less digits than its factorization.

21453505440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3139 (or 3131 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 33.

The spelling of 21453505440 in words is "twenty-one billion, four hundred fifty-three million, five hundred five thousand, four hundred forty".