81078523 has 2 divisors, whose sum is σ = 81078524. Its totient is φ = 81078522.

The previous prime is 81078497. The next prime is 81078527. The reversal of 81078523 is 32587018.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81078523 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is not a weakly prime, because it can be changed into another prime (81078527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40539261 + 40539262.

It is an arithmetic number, because the mean of its divisors is an integer number (40539262).

Almost surely, 2^81078523 is an apocalyptic number.

81078523 is a deficient number, since it is larger than the sum of its proper divisors (1).

81078523 is an equidigital number, since it uses as much as digits as its factorization.

81078523 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 81078523 is about 9004.3613321545. The cubic root of 81078523 is about 432.8146404591.

The spelling of 81078523 in words is "eighty-one million, seventy-eight thousand, five hundred twenty-three".