21210211444 has 6 divisors (see below), whose sum is σ = 37117870034. Its totient is φ = 10605105720.

The previous prime is 21210211403. The next prime is 21210211459. The reversal of 21210211444 is 44411201212.

It can be written as a sum of positive squares in only one way, i.e., 18615327844 + 2594883600 = 136438^2 + 50940^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2651276427 + ... + 2651276434.

Almost surely, 2^21210211444 is an apocalyptic number.

It is an amenable number.

21210211444 is a deficient number, since it is larger than the sum of its proper divisors (15907658590).

21210211444 is a wasteful number, since it uses less digits than its factorization.

21210211444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5302552865 (or 5302552863 counting only the distinct ones).

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

Adding to 21210211444 its reverse (44411201212), we get a palindrome (65621412656).

The spelling of 21210211444 in words is "twenty-one billion, two hundred ten million, two hundred eleven thousand, four hundred forty-four".