21105540344 has 16 divisors (see below), whose sum is σ = 45226158000. Its totient is φ = 9045231552.

The previous prime is 21105540331. The next prime is 21105540359. The reversal of 21105540344 is 44304550112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 188442269 + ... + 188442380.

It is an arithmetic number, because the mean of its divisors is an integer number (2826634875).

Almost surely, 2^21105540344 is an apocalyptic number.

It is an amenable number.

21105540344 is an abundant number, since it is smaller than the sum of its proper divisors (24120617656).

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

21105540344 is a wasteful number, since it uses less digits than its factorization.

21105540344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 376884662 (or 376884658 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The spelling of 21105540344 in words is "twenty-one billion, one hundred five million, five hundred forty thousand, three hundred forty-four".