815816200401 has 12 divisors (see below), whose sum is σ = 1179456162612. Its totient is φ = 543390551136.

The previous prime is 815816200361. The next prime is 815816200427. The reversal of 815816200401 is 104002618518.

It can be written as a sum of positive squares in 2 ways, for example, as 70833161025 + 744983039376 = 266145^2 + 863124^2 .

It is not a de Polignac number, because 815816200401 - 2⁷ = 815816200273 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (815816200481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40565706 + ... + 40585811.

It is an arithmetic number, because the mean of its divisors is an integer number (98288013551).

Almost surely, 2^815816200401 is an apocalyptic number.

It is an amenable number.

815816200401 is a deficient number, since it is larger than the sum of its proper divisors (363639962211).

815816200401 is a wasteful number, since it uses less digits than its factorization.

815816200401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81152640 (or 81152637 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

Adding to 815816200401 its reverse (104002618518), we get a palindrome (919818818919).

The spelling of 815816200401 in words is "eight hundred fifteen billion, eight hundred sixteen million, two hundred thousand, four hundred one".