21213334144 has 16 divisors (see below), whose sum is σ = 42260939370. Its totient is φ = 10606667008.

The previous prime is 21213334139. The next prime is 21213334159. The reversal of 21213334144 is 44143331212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 15267073600 + 5946260544 = 123560^2 + 77112^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82864459 + ... + 82864714.

Almost surely, 2^21213334144 is an apocalyptic number.

It is an amenable number.

21213334144 is a deficient number, since it is larger than the sum of its proper divisors (21047605226).

21213334144 is an equidigital number, since it uses as much as digits as its factorization.

21213334144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165729187 (or 165729175 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

Adding to 21213334144 its reverse (44143331212), we get a palindrome (65356665356).

The spelling of 21213334144 in words is "twenty-one billion, two hundred thirteen million, three hundred thirty-four thousand, one hundred forty-four".