21010532550 has 96 divisors (see below), whose sum is σ = 59607684864. Its totient is φ = 4797744000.

The previous prime is 21010532549. The next prime is 21010532563. The reversal of 21010532550 is 5523501012.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 21010532550.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1136380 + ... + 1154720.

It is an arithmetic number, because the mean of its divisors is an integer number (620913384).

Almost surely, 2^21010532550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21010532550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29803842432).

21010532550 is an abundant number, since it is smaller than the sum of its proper divisors (38597152314).

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

21010532550 is a wasteful number, since it uses less digits than its factorization.

21010532550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19454 (or 19449 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 24.

The spelling of 21010532550 in words is "twenty-one billion, ten million, five hundred thirty-two thousand, five hundred fifty".