21653065361205 has 12 divisors (see below), whose sum is σ = 37531979959500. Its totient is φ = 11548301525952.

The previous prime is 21653065361197. The next prime is 21653065361267. The reversal of 21653065361205 is 50216356035612.

21653065361205 is a `hidden beast` number, since 2 + 1 + 6 + 530 + 6 + 53 + 61 + 2 + 0 + 5 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15566552029809 + 6086513331396 = 3945447^2 + 2467086^2 .

It is not a de Polignac number, because 21653065361205 - 2³ = 21653065361197 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 481179230249 = 21653065361205 / (2 + 1 + 6 + 5 + 3 + 0 + 6 + 5 + 3 + 6 + 1 + 2 + 0 + 5).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 240589615080 + ... + 240589615169.

It is an arithmetic number, because the mean of its divisors is an integer number (3127664996625).

Almost surely, 2^{21653065361205} is an apocalyptic number.

It is an amenable number.

21653065361205 is a deficient number, since it is larger than the sum of its proper divisors (15878914598295).

21653065361205 is a wasteful number, since it uses less digits than its factorization.

21653065361205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481179230260 (or 481179230257 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The spelling of 21653065361205 in words is "twenty-one trillion, six hundred fifty-three billion, sixty-five million, three hundred sixty-one thousand, two hundred five".