819747879481 has 2 divisors, whose sum is σ = 819747879482. Its totient is φ = 819747879480.

The previous prime is 819747879437. The next prime is 819747879581. The reversal of 819747879481 is 184978747918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 514066056256 + 305681823225 = 716984^2 + 552885^2 .

It is a cyclic number.

It is not a de Polignac number, because 819747879481 - 2²⁷ = 819613661753 is a prime.

It is a super-2 number, since 2×819747879481² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (819747879581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 409873939740 + 409873939741.

It is an arithmetic number, because the mean of its divisors is an integer number (409873939741).

Almost surely, 2^819747879481 is an apocalyptic number.

It is an amenable number.

819747879481 is a deficient number, since it is larger than the sum of its proper divisors (1).

819747879481 is an equidigital number, since it uses as much as digits as its factorization.

819747879481 is an evil number, because the sum of its binary digits is even.

The product of its digits is 227598336, while the sum is 73.

The spelling of 819747879481 in words is "eight hundred nineteen billion, seven hundred forty-seven million, eight hundred seventy-nine thousand, four hundred eighty-one".