21655420600225 has 24 divisors (see below), whose sum is σ = 26950761025272. Its totient is φ = 17261113267200.

The previous prime is 21655420600211. The next prime is 21655420600241. The reversal of 21655420600225 is 52200602455612.

It can be written as a sum of positive squares in 12 ways, for example, as 188943224976 + 21466477375249 = 434676^2 + 4633193^2 .

It is not a de Polignac number, because 21655420600225 - 2⁹ = 21655420599713 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30716779 + ... + 31413871.

It is an arithmetic number, because the mean of its divisors is an integer number (1122948376053).

Almost surely, 2^{21655420600225} is an apocalyptic number.

21655420600225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21655420600225 is a deficient number, since it is larger than the sum of its proper divisors (5295340425047).

21655420600225 is a wasteful number, since it uses less digits than its factorization.

21655420600225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701637 (or 701632 counting only the distinct ones).

The product of its (nonzero) digits is 288000, while the sum is 40.

The spelling of 21655420600225 in words is "twenty-one trillion, six hundred fifty-five billion, four hundred twenty million, six hundred thousand, two hundred twenty-five".