21553225540 has 192 divisors, whose sum is σ = 58525286400. Its totient is φ = 6470553600.

The previous prime is 21553225537. The next prime is 21553225541. The reversal of 21553225540 is 4552235512.

It is a junction number, because it is equal to n+sod(n) for n = 21553225496 and 21553225505.

It is not an unprimeable number, because it can be changed into a prime (21553225541) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 11408916 + ... + 11410804.

It is an arithmetic number, because the mean of its divisors is an integer number (304819200).

Almost surely, 2^21553225540 is an apocalyptic number.

21553225540 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 21553225540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29262643200).

21553225540 is an abundant number, since it is smaller than the sum of its proper divisors (36972060860).

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

21553225540 is a wasteful number, since it uses less digits than its factorization.

21553225540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2186 (or 2184 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 34.

The spelling of 21553225540 in words is "twenty-one billion, five hundred fifty-three million, two hundred twenty-five thousand, five hundred forty".