81614517913 has 2 divisors, whose sum is σ = 81614517914. Its totient is φ = 81614517912.

The previous prime is 81614517889. The next prime is 81614517947. The reversal of 81614517913 is 31971541618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81606206224 + 8311689 = 285668^2 + 2883^2 .

It is a cyclic number.

It is not a de Polignac number, because 81614517913 - 2³³ = 73024583321 is a prime.

It is not a weakly prime, because it can be changed into another prime (81614517953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40807258956 + 40807258957.

It is an arithmetic number, because the mean of its divisors is an integer number (40807258957).

Almost surely, 2^81614517913 is an apocalyptic number.

It is an amenable number.

81614517913 is a deficient number, since it is larger than the sum of its proper divisors (1).

81614517913 is an equidigital number, since it uses as much as digits as its factorization.

81614517913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 181440, while the sum is 46.

The spelling of 81614517913 in words is "eighty-one billion, six hundred fourteen million, five hundred seventeen thousand, nine hundred thirteen".