81930452249 has 2 divisors, whose sum is σ = 81930452250. Its totient is φ = 81930452248.

The previous prime is 81930452167. The next prime is 81930452287. The reversal of 81930452249 is 94225403918.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81838905625 + 91546624 = 286075^2 + 9568^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81930452249 is a prime.

It is not a weakly prime, because it can be changed into another prime (81930452449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40965226124 + 40965226125.

It is an arithmetic number, because the mean of its divisors is an integer number (40965226125).

Almost surely, 2^81930452249 is an apocalyptic number.

It is an amenable number.

81930452249 is a deficient number, since it is larger than the sum of its proper divisors (1).

81930452249 is an equidigital number, since it uses as much as digits as its factorization.

81930452249 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 622080, while the sum is 47.

The spelling of 81930452249 in words is "eighty-one billion, nine hundred thirty million, four hundred fifty-two thousand, two hundred forty-nine".