21540223457552 has 20 divisors (see below), whose sum is σ = 41736243405516. Its totient is φ = 10769579998080.

The previous prime is 21540223457537. The next prime is 21540223457591. The reversal of 21540223457552 is 25575432204512.

It can be written as a sum of positive squares in 2 ways, for example, as 3898745026576 + 17641478430976 = 1974524^2 + 4200176^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21540223457497 and 21540223457506.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32898863 + ... + 33547214.

Almost surely, 2^{21540223457552} is an apocalyptic number.

It is an amenable number.

21540223457552 is a deficient number, since it is larger than the sum of its proper divisors (20196019947964).

21540223457552 is a wasteful number, since it uses less digits than its factorization.

21540223457552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66466346 (or 66466340 counting only the distinct ones).

The product of its (nonzero) digits is 3360000, while the sum is 47.

The spelling of 21540223457552 in words is "twenty-one trillion, five hundred forty billion, two hundred twenty-three million, four hundred fifty-seven thousand, five hundred fifty-two".