21517225071 has 8 divisors (see below), whose sum is σ = 29117837184. Its totient is φ = 14130714840.

The previous prime is 21517225049. The next prime is 21517225141. The reversal of 21517225071 is 17052271512.

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

It is not a de Polignac number, because 21517225071 - 2⁷ = 21517224943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21517225001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53525235 + ... + 53525636.

It is an arithmetic number, because the mean of its divisors is an integer number (3639729648).

Almost surely, 2^21517225071 is an apocalyptic number.

21517225071 is a deficient number, since it is larger than the sum of its proper divisors (7600612113).

21517225071 is a wasteful number, since it uses less digits than its factorization.

21517225071 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107050941.

The product of its (nonzero) digits is 9800, while the sum is 33.

Adding to 21517225071 its reverse (17052271512), we get a palindrome (38569496583).

The spelling of 21517225071 in words is "twenty-one billion, five hundred seventeen million, two hundred twenty-five thousand, seventy-one".