81379297 has 2 divisors, whose sum is σ = 81379298. Its totient is φ = 81379296.

The previous prime is 81379283. The next prime is 81379303. The reversal of 81379297 is 79297318.

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., 74805201 + 6574096 = 8649^2 + 2564^2 .

It is a cyclic number.

It is not a de Polignac number, because 81379297 - 2²³ = 72990689 is a prime.

It is not a weakly prime, because it can be changed into another prime (81379997) 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, 40689648 + 40689649.

It is an arithmetic number, because the mean of its divisors is an integer number (40689649).

Almost surely, 2^81379297 is an apocalyptic number.

It is an amenable number.

81379297 is a deficient number, since it is larger than the sum of its proper divisors (1).

81379297 is an equidigital number, since it uses as much as digits as its factorization.

81379297 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 190512, while the sum is 46.

The square root of 81379297 is about 9021.0474447261. The cubic root of 81379297 is about 433.3491788420.

The spelling of 81379297 in words is "eighty-one million, three hundred seventy-nine thousand, two hundred ninety-seven".