16511217408 has 216 divisors, whose sum is σ = 55099699200. Its totient is φ = 4657416192.

The previous prime is 16511217407. The next prime is 16511217439. The reversal of 16511217408 is 80471211561.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16511217407) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1267633 + ... + 1280591.

It is an arithmetic number, because the mean of its divisors is an integer number (255091200).

Almost surely, 2^16511217408 is an apocalyptic number.

16511217408 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16511217408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27549849600).

16511217408 is an abundant number, since it is smaller than the sum of its proper divisors (38588481792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16511217408 is a wasteful number, since it uses less digits than its factorization.

16511217408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13067 (or 13050 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

Adding to 16511217408 its reverse (80471211561), we get a palindrome (96982428969).

The spelling of 16511217408 in words is "sixteen billion, five hundred eleven million, two hundred seventeen thousand, four hundred eight".