21164360550 has 24 divisors (see below), whose sum is σ = 52487614536. Its totient is φ = 5643829440.

The previous prime is 21164360537. The next prime is 21164360551. The reversal of 21164360550 is 5506346112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21164360551) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 70547719 + ... + 70548018.

It is an arithmetic number, because the mean of its divisors is an integer number (2186983939).

Almost surely, 2^21164360550 is an apocalyptic number.

21164360550 is an abundant number, since it is smaller than the sum of its proper divisors (31323253986).

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

21164360550 is a wasteful number, since it uses less digits than its factorization.

21164360550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 141095752 (or 141095747 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The spelling of 21164360550 in words is "twenty-one billion, one hundred sixty-four million, three hundred sixty thousand, five hundred fifty".