6642816511 has 4 divisors (see below), whose sum is σ = 6649260624. Its totient is φ = 6636372400.

The previous prime is 6642816421. The next prime is 6642816541. The reversal of 6642816511 is 1156182466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6642816511 - 2²⁷ = 6508598783 is a prime.

It is a super-2 number, since 2×6642816511² = 88254022397628426242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6642816541) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3220510 + ... + 3222571.

It is an arithmetic number, because the mean of its divisors is an integer number (1662315156).

Almost surely, 2^6642816511 is an apocalyptic number.

6642816511 is a deficient number, since it is larger than the sum of its proper divisors (6444113).

6642816511 is a wasteful number, since it uses less digits than its factorization.

6642816511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6444112.

The product of its digits is 69120, while the sum is 40.

The square root of 6642816511 is about 81503.4754535044. The cubic root of 6642816511 is about 1879.8249904049.

Adding to 6642816511 its reverse (1156182466), we get a palindrome (7798998977).

The spelling of 6642816511 in words is "six billion, six hundred forty-two million, eight hundred sixteen thousand, five hundred eleven".