21201105510 has 128 divisors (see below), whose sum is σ = 61028352000. Its totient is φ = 5206467456.

The previous prime is 21201105509. The next prime is 21201105533. The reversal of 21201105510 is 1550110212.

21201105510 is a `hidden beast` number, since 2 + 1 + 2 + 0 + 110 + 551 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1534011 + ... + 1547769.

It is an arithmetic number, because the mean of its divisors is an integer number (476784000).

Almost surely, 2^21201105510 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201105510, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30514176000).

21201105510 is an abundant number, since it is smaller than the sum of its proper divisors (39827246490).

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

21201105510 is a wasteful number, since it uses less digits than its factorization.

21201105510 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14227 (or 14221 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 18.

Adding to 21201105510 its reverse (1550110212), we get a palindrome (22751215722).

The spelling of 21201105510 in words is "twenty-one billion, two hundred one million, one hundred five thousand, five hundred ten".