81329077 has 2 divisors, whose sum is σ = 81329078. Its totient is φ = 81329076.

The previous prime is 81329069. The next prime is 81329107. The reversal of 81329077 is 77092318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75881521 + 5447556 = 8711^2 + 2334^2 .

It is a cyclic number.

It is not a de Polignac number, because 81329077 - 2³ = 81329069 is a prime.

It is a super-2 number, since 2×81329077² = 13228837531343858, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81329047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40664538 + 40664539.

It is an arithmetic number, because the mean of its divisors is an integer number (40664539).

Almost surely, 2^81329077 is an apocalyptic number.

It is an amenable number.

81329077 is a deficient number, since it is larger than the sum of its proper divisors (1).

81329077 is an equidigital number, since it uses as much as digits as its factorization.

81329077 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 81329077 is about 9018.2635246482. The cubic root of 81329077 is about 433.2600190893.

It can be divided in two parts, 813 and 29077, that added together give a triangular number (29890 = T₂₄₄).

The spelling of 81329077 in words is "eighty-one million, three hundred twenty-nine thousand, seventy-seven".