21111444004 has 36 divisors (see below), whose sum is σ = 43459790220. Its totient is φ = 8946094080.

The previous prime is 21111443963. The next prime is 21111444017. The reversal of 21111444004 is 40044411112.

It can be written as a sum of positive squares in 2 ways, for example, as 13479674404 + 7631769600 = 116102^2 + 87360^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 587677 + ... + 622564.

It is an arithmetic number, because the mean of its divisors is an integer number (1207216395).

Almost surely, 2^21111444004 is an apocalyptic number.

It is an amenable number.

21111444004 is an abundant number, since it is smaller than the sum of its proper divisors (22348346216).

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

21111444004 is a wasteful number, since it uses less digits than its factorization.

21111444004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1210348 (or 1210339 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

Adding to 21111444004 its reverse (40044411112), we get a palindrome (61155855116).

The spelling of 21111444004 in words is "twenty-one billion, one hundred eleven million, four hundred forty-four thousand, four".