81333900779 has 2 divisors, whose sum is σ = 81333900780. Its totient is φ = 81333900778.

The previous prime is 81333900629. The next prime is 81333900787. The reversal of 81333900779 is 97700933318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81333900779 - 2⁸ = 81333900523 is a prime.

It is not a weakly prime, because it can be changed into another prime (81333900079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40666950389 + 40666950390.

It is an arithmetic number, because the mean of its divisors is an integer number (40666950390).

Almost surely, 2^81333900779 is an apocalyptic number.

81333900779 is a deficient number, since it is larger than the sum of its proper divisors (1).

81333900779 is an equidigital number, since it uses as much as digits as its factorization.

81333900779 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 857304, while the sum is 50.

The spelling of 81333900779 in words is "eighty-one billion, three hundred thirty-three million, nine hundred thousand, seven hundred seventy-nine".