810538490981 has 2 divisors, whose sum is σ = 810538490982. Its totient is φ = 810538490980.

The previous prime is 810538490959. The next prime is 810538491017. The reversal of 810538490981 is 189094835018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 759322274881 + 51216216100 = 871391^2 + 226310^2 .

It is a cyclic number.

It is not a de Polignac number, because 810538490981 - 2³⁰ = 809464749157 is a prime.

It is a super-2 number, since 2×810538490981² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (810538490581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405269245490 + 405269245491.

It is an arithmetic number, because the mean of its divisors is an integer number (405269245491).

Almost surely, 2^810538490981 is an apocalyptic number.

It is an amenable number.

810538490981 is a deficient number, since it is larger than the sum of its proper divisors (1).

810538490981 is an equidigital number, since it uses as much as digits as its factorization.

810538490981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2488320, while the sum is 56.

The spelling of 810538490981 in words is "eight hundred ten billion, five hundred thirty-eight million, four hundred ninety thousand, nine hundred eighty-one".