81480685849 has 2 divisors, whose sum is σ = 81480685850. Its totient is φ = 81480685848.

The previous prime is 81480685829. The next prime is 81480685901. The reversal of 81480685849 is 94858608418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 74977392400 + 6503293449 = 273820^2 + 80643^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81480685849 is a prime.

It is not a weakly prime, because it can be changed into another prime (81480685829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40740342924 + 40740342925.

It is an arithmetic number, because the mean of its divisors is an integer number (40740342925).

Almost surely, 2^81480685849 is an apocalyptic number.

It is an amenable number.

81480685849 is a deficient number, since it is larger than the sum of its proper divisors (1).

81480685849 is an equidigital number, since it uses as much as digits as its factorization.

81480685849 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17694720, while the sum is 61.

The spelling of 81480685849 in words is "eighty-one billion, four hundred eighty million, six hundred eighty-five thousand, eight hundred forty-nine".