21001504144 has 40 divisors (see below), whose sum is σ = 41142163608. Its totient is φ = 10384343040.

The previous prime is 21001504141. The next prime is 21001504201. The reversal of 21001504144 is 44140510012.

It can be written as a sum of positive squares in 4 ways, for example, as 2016400 + 20999487744 = 1420^2 + 144912^2 .

It is not an unprimeable number, because it can be changed into a prime (21001504141) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2293944 + ... + 2303080.

Almost surely, 2^21001504144 is an apocalyptic number.

It is an amenable number.

21001504144 is a deficient number, since it is larger than the sum of its proper divisors (20140659464).

21001504144 is a wasteful number, since it uses less digits than its factorization.

21001504144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10723 (or 10717 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The spelling of 21001504144 in words is "twenty-one billion, one million, five hundred four thousand, one hundred forty-four".