21326033550 has 96 divisors (see below), whose sum is σ = 55238464512. Its totient is φ = 5434718080.

The previous prime is 21326033549. The next prime is 21326033551. The reversal of 21326033550 is 5533062312.

It is an interprime number because it is at equal distance from previous prime (21326033549) and next prime (21326033551).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21326033551) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5128072 + ... + 5132228.

It is an arithmetic number, because the mean of its divisors is an integer number (575400672).

Almost surely, 2^21326033550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21326033550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27619232256).

21326033550 is an abundant number, since it is smaller than the sum of its proper divisors (33912430962).

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

21326033550 is a wasteful number, since it uses less digits than its factorization.

21326033550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5682 (or 5677 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 30.

Adding to 21326033550 its reverse (5533062312), we get a palindrome (26859095862).

The spelling of 21326033550 in words is "twenty-one billion, three hundred twenty-six million, thirty-three thousand, five hundred fifty".