81586778153 has 2 divisors, whose sum is σ = 81586778154. Its totient is φ = 81586778152.

The previous prime is 81586778111. The next prime is 81586778167. The reversal of 81586778153 is 35187768518.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 57229557529 + 24357220624 = 239227^2 + 156068^2 .

It is a cyclic number.

It is not a de Polignac number, because 81586778153 - 2⁶ = 81586778089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81586778092 and 81586778101.

It is not a weakly prime, because it can be changed into another prime (81586778653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40793389076 + 40793389077.

It is an arithmetic number, because the mean of its divisors is an integer number (40793389077).

Almost surely, 2^81586778153 is an apocalyptic number.

It is an amenable number.

81586778153 is a deficient number, since it is larger than the sum of its proper divisors (1).

81586778153 is an equidigital number, since it uses as much as digits as its factorization.

81586778153 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11289600, while the sum is 59.

The spelling of 81586778153 in words is "eighty-one billion, five hundred eighty-six million, seven hundred seventy-eight thousand, one hundred fifty-three".