21051066244 has 24 divisors (see below), whose sum is σ = 41041206360. Its totient is φ = 9380845824.

The previous prime is 21051066209. The next prime is 21051066277. The reversal of 21051066244 is 44266015012.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 340402500 + 20710663744 = 18450^2 + 143912^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6978289 + ... + 6981304.

It is an arithmetic number, because the mean of its divisors is an integer number (1710050265).

Almost surely, 2^21051066244 is an apocalyptic number.

It is an amenable number.

21051066244 is a deficient number, since it is larger than the sum of its proper divisors (19990140116).

21051066244 is a wasteful number, since it uses less digits than its factorization.

21051066244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13959639 (or 13959637 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The spelling of 21051066244 in words is "twenty-one billion, fifty-one million, sixty-six thousand, two hundred forty-four".