81914976449 has 2 divisors, whose sum is σ = 81914976450. Its totient is φ = 81914976448.

The previous prime is 81914976443. The next prime is 81914976457. The reversal of 81914976449 is 94467941918.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81720513424 + 194463025 = 285868^2 + 13945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81914976449 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81914976391 and 81914976400.

It is not a weakly prime, because it can be changed into another prime (81914976443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40957488224 + 40957488225.

It is an arithmetic number, because the mean of its divisors is an integer number (40957488225).

Almost surely, 2^81914976449 is an apocalyptic number.

It is an amenable number.

81914976449 is a deficient number, since it is larger than the sum of its proper divisors (1).

81914976449 is an equidigital number, since it uses as much as digits as its factorization.

81914976449 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15676416, while the sum is 62.

It can be divided in two parts, 819149 and 76449, that added together give a palindrome (895598).

The spelling of 81914976449 in words is "eighty-one billion, nine hundred fourteen million, nine hundred seventy-six thousand, four hundred forty-nine".