81598886477 has 2 divisors, whose sum is σ = 81598886478. Its totient is φ = 81598886476.

The previous prime is 81598886471. The next prime is 81598886513. The reversal of 81598886477 is 77468889518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 70516271401 + 11082615076 = 265549^2 + 105274^2 .

It is a cyclic number.

It is not a de Polignac number, because 81598886477 - 2¹² = 81598882381 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81598886477.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81598886471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40799443238 + 40799443239.

It is an arithmetic number, because the mean of its divisors is an integer number (40799443239).

Almost surely, 2^81598886477 is an apocalyptic number.

It is an amenable number.

81598886477 is a deficient number, since it is larger than the sum of its proper divisors (1).

81598886477 is an equidigital number, since it uses as much as digits as its factorization.

81598886477 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216760320, while the sum is 71.

The spelling of 81598886477 in words is "eighty-one billion, five hundred ninety-eight million, eight hundred eighty-six thousand, four hundred seventy-seven".