81298470769 has 2 divisors, whose sum is σ = 81298470770. Its totient is φ = 81298470768.

The previous prime is 81298470647. The next prime is 81298470787. The reversal of 81298470769 is 96707489218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78406720144 + 2891750625 = 280012^2 + 53775^2 .

It is a cyclic number.

It is not a de Polignac number, because 81298470769 - 2²¹ = 81296373617 is a prime.

It is a super-2 number, since 2×81298470769² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81298450769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40649235384 + 40649235385.

It is an arithmetic number, because the mean of its divisors is an integer number (40649235385).

Almost surely, 2^81298470769 is an apocalyptic number.

It is an amenable number.

81298470769 is a deficient number, since it is larger than the sum of its proper divisors (1).

81298470769 is an equidigital number, since it uses as much as digits as its factorization.

81298470769 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12192768, while the sum is 61.

The spelling of 81298470769 in words is "eighty-one billion, two hundred ninety-eight million, four hundred seventy thousand, seven hundred sixty-nine".