21044321151440 has 40 divisors (see below), whose sum is σ = 49084366373448. Its totient is φ = 8390834749440.

The previous prime is 21044321151367. The next prime is 21044321151457. The reversal of 21044321151440 is 4415112344012.

It can be written as a sum of positive squares in 4 ways, for example, as 1014435724864 + 20029885426576 = 1007192^2 + 4475476^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 21044321151397 and 21044321151406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 420189041 + ... + 420239120.

Almost surely, 2^{21044321151440} is an apocalyptic number.

21044321151440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21044321151440 is an abundant number, since it is smaller than the sum of its proper divisors (28040045222008).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21044321151440 is a wasteful number, since it uses less digits than its factorization.

21044321151440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840428487 (or 840428481 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 32.

Adding to 21044321151440 its reverse (4415112344012), we get a palindrome (25459433495452).

The spelling of 21044321151440 in words is "twenty-one trillion, forty-four billion, three hundred twenty-one million, one hundred fifty-one thousand, four hundred forty".