819877006121 has 2 divisors, whose sum is σ = 819877006122. Its totient is φ = 819877006120.

The previous prime is 819877006033. The next prime is 819877006139. The reversal of 819877006121 is 121600778918.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 770903316121 + 48973690000 = 878011^2 + 221300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-819877006121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 819877006121.

It is not a weakly prime, because it can be changed into another prime (819877008121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409938503060 + 409938503061.

It is an arithmetic number, because the mean of its divisors is an integer number (409938503061).

Almost surely, 2^819877006121 is an apocalyptic number.

It is an amenable number.

819877006121 is a deficient number, since it is larger than the sum of its proper divisors (1).

819877006121 is an equidigital number, since it uses as much as digits as its factorization.

819877006121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 338688, while the sum is 50.

The spelling of 819877006121 in words is "eight hundred nineteen billion, eight hundred seventy-seven million, six thousand, one hundred twenty-one".