21011105346 has 128 divisors (see below), whose sum is σ = 54738063360. Its totient is φ = 5216736000.

The previous prime is 21011105299. The next prime is 21011105359. The reversal of 21011105346 is 64350111012.

It is a happy number.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1345435 + ... + 1360961.

It is an arithmetic number, because the mean of its divisors is an integer number (427641120).

Almost surely, 2^21011105346 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21011105346, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27369031680).

21011105346 is an abundant number, since it is smaller than the sum of its proper divisors (33726958014).

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

21011105346 is a wasteful number, since it uses less digits than its factorization.

21011105346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15680.

The product of its (nonzero) digits is 720, while the sum is 24.

Adding to 21011105346 its reverse (64350111012), we get a palindrome (85361216358).

The spelling of 21011105346 in words is "twenty-one billion, eleven million, one hundred five thousand, three hundred forty-six".