811421209138 has 24 divisors (see below), whose sum is σ = 1272661244316. Its totient is φ = 387976512000.

The previous prime is 811421209051. The next prime is 811421209141. The reversal of 811421209138 is 831902124118.

811421209138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 811183031649 + 238177489 = 900657^2 + 15433^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 811421209138.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4353378 + ... + 4535938.

Almost surely, 2^811421209138 is an apocalyptic number.

811421209138 is a deficient number, since it is larger than the sum of its proper divisors (461240035178).

811421209138 is a wasteful number, since it uses less digits than its factorization.

811421209138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186810 (or 186787 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 40.

The spelling of 811421209138 in words is "eight hundred eleven billion, four hundred twenty-one million, two hundred nine thousand, one hundred thirty-eight".