81407329 has 2 divisors, whose sum is σ = 81407330. Its totient is φ = 81407328.

The previous prime is 81407317. The next prime is 81407351. The reversal of 81407329 is 92370418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79299025 + 2108304 = 8905^2 + 1452^2 .

It is a cyclic number.

It is not a de Polignac number, because 81407329 - 2⁹ = 81406817 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81407294 and 81407303.

It is not a weakly prime, because it can be changed into another prime (81407429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40703664 + 40703665.

It is an arithmetic number, because the mean of its divisors is an integer number (40703665).

Almost surely, 2^81407329 is an apocalyptic number.

It is an amenable number.

81407329 is a deficient number, since it is larger than the sum of its proper divisors (1).

81407329 is an equidigital number, since it uses as much as digits as its factorization.

81407329 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 81407329 is about 9022.6010107951. The cubic root of 81407329 is about 433.3989304377.

The spelling of 81407329 in words is "eighty-one million, four hundred seven thousand, three hundred twenty-nine".