21517032727055 has 8 divisors (see below), whose sum is σ = 26653356668544. Its totient is φ = 16658347917600.

The previous prime is 21517032727039. The next prime is 21517032727061. The reversal of 21517032727055 is 55072723071512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21517032727055 - 2⁴ = 21517032727039 is a prime.

It is a Duffinian number.

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, 69409782836 + ... + 69409783145.

It is an arithmetic number, because the mean of its divisors is an integer number (3331669583568).

Almost surely, 2^{21517032727055} is an apocalyptic number.

21517032727055 is a deficient number, since it is larger than the sum of its proper divisors (5136323941489).

21517032727055 is a wasteful number, since it uses less digits than its factorization.

21517032727055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138819566017.

The product of its (nonzero) digits is 1029000, while the sum is 47.

Adding to 21517032727055 its reverse (55072723071512), we get a palindrome (76589755798567).

The spelling of 21517032727055 in words is "twenty-one trillion, five hundred seventeen billion, thirty-two million, seven hundred twenty-seven thousand, fifty-five".