21144401228 has 24 divisors (see below), whose sum is σ = 37553322240. Its totient is φ = 10415114640.

The previous prime is 21144401221. The next prime is 21144401279. The reversal of 21144401228 is 82210444112.

It is a self number, because there is not a number n which added to its sum of digits gives 21144401228.

It is not an unprimeable number, because it can be changed into a prime (21144401221) by changing a digit.

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, 341483 + ... + 398621.

It is an arithmetic number, because the mean of its divisors is an integer number (1564721760).

Almost surely, 2^21144401228 is an apocalyptic number.

It is an amenable number.

21144401228 is a deficient number, since it is larger than the sum of its proper divisors (16408921012).

21144401228 is a wasteful number, since it uses less digits than its factorization.

21144401228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58517 (or 58515 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The spelling of 21144401228 in words is "twenty-one billion, one hundred forty-four million, four hundred one thousand, two hundred twenty-eight".