816815811 has 32 divisors (see below), whose sum is σ = 1280885760. Its totient is φ = 453223296.

The previous prime is 816815809. The next prime is 816815837. The reversal of 816815811 is 118518618.

It is not a de Polignac number, because 816815811 - 2¹ = 816815809 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 816815811.

It is not an unprimeable number, because it can be changed into a prime (816815891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 618610 + ... + 619928.

It is an arithmetic number, because the mean of its divisors is an integer number (40027680).

Almost surely, 2^816815811 is an apocalyptic number.

816815811 is a deficient number, since it is larger than the sum of its proper divisors (464069949).

816815811 is a wasteful number, since it uses less digits than its factorization.

816815811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2163.

The product of its digits is 15360, while the sum is 39.

The square root of 816815811 is about 28579.9896955895. The cubic root of 816815811 is about 934.7770583829. Note that the first 3 decimals are identical.

The spelling of 816815811 in words is "eight hundred sixteen million, eight hundred fifteen thousand, eight hundred eleven".