21365705305552 has 20 divisors (see below), whose sum is σ = 41396452724196. Its totient is φ = 10682749763840.

The previous prime is 21365705305517. The next prime is 21365705305619. The reversal of 21365705305552 is 25550350756312.

It can be written as a sum of positive squares in 2 ways, for example, as 13342626395536 + 8023078910016 = 3652756^2 + 2832504^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21365705305496 and 21365705305505.

It is a congruent number.

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, 4703323 + ... + 8053114.

Almost surely, 2^{21365705305552} is an apocalyptic number.

It is an amenable number.

21365705305552 is a deficient number, since it is larger than the sum of its proper divisors (20030747418644).

21365705305552 is a wasteful number, since it uses less digits than its factorization.

21365705305552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12861126 (or 12861120 counting only the distinct ones).

The product of its (nonzero) digits is 4725000, while the sum is 49.

The spelling of 21365705305552 in words is "twenty-one trillion, three hundred sixty-five billion, seven hundred five million, three hundred five thousand, five hundred fifty-two".