21224957550 has 144 divisors (see below), whose sum is σ = 54960625152. Its totient is φ = 5415076800.

The previous prime is 21224957549. The next prime is 21224957563. The reversal of 21224957550 is 5575942212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 74999709 + ... + 74999991.

It is an arithmetic number, because the mean of its divisors is an integer number (381671008).

Almost surely, 2^21224957550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21224957550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27480312576).

21224957550 is an abundant number, since it is smaller than the sum of its proper divisors (33735667602).

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

21224957550 is a wasteful number, since it uses less digits than its factorization.

21224957550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583 (or 451 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 42.

The spelling of 21224957550 in words is "twenty-one billion, two hundred twenty-four million, nine hundred fifty-seven thousand, five hundred fifty".