16520072217 has 16 divisors (see below), whose sum is σ = 24043470528. Its totient is φ = 10006217280.

The previous prime is 16520072213. The next prime is 16520072249. The reversal of 16520072217 is 71227002561.

It is not a de Polignac number, because 16520072217 - 2² = 16520072213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (16520072213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 91978 + ... + 203715.

It is an arithmetic number, because the mean of its divisors is an integer number (1502716908).

Almost surely, 2^16520072217 is an apocalyptic number.

It is an amenable number.

16520072217 is a deficient number, since it is larger than the sum of its proper divisors (7523398311).

16520072217 is a wasteful number, since it uses less digits than its factorization.

16520072217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 297400.

The product of its (nonzero) digits is 11760, while the sum is 33.

Adding to 16520072217 its reverse (71227002561), we get a palindrome (87747074778).

The spelling of 16520072217 in words is "sixteen billion, five hundred twenty million, seventy-two thousand, two hundred seventeen".