21004144144 has 10 divisors (see below), whose sum is σ = 40695529310. Its totient is φ = 10502072064.

The previous prime is 21004144093. The next prime is 21004144229. The reversal of 21004144144 is 44144140012.

It can be written as a sum of positive squares in only one way, i.e., 12615782400 + 8388361744 = 112320^2 + 91588^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 656379489 + ... + 656379520.

It is an arithmetic number, because the mean of its divisors is an integer number (4069552931).

Almost surely, 2^21004144144 is an apocalyptic number.

It is an amenable number.

21004144144 is a deficient number, since it is larger than the sum of its proper divisors (19691385166).

21004144144 is a wasteful number, since it uses less digits than its factorization.

21004144144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1312759017 (or 1312759011 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 25.

Adding to 21004144144 its reverse (44144140012), we get a palindrome (65148284156).

The spelling of 21004144144 in words is "twenty-one billion, four million, one hundred forty-four thousand, one hundred forty-four".