81179291 has 2 divisors, whose sum is σ = 81179292. Its totient is φ = 81179290.

The previous prime is 81179269. The next prime is 81179309. The reversal of 81179291 is 19297118.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81179291 is a prime.

It is not a weakly prime, because it can be changed into another prime (81178291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40589645 + 40589646.

It is an arithmetic number, because the mean of its divisors is an integer number (40589646).

Almost surely, 2^81179291 is an apocalyptic number.

81179291 is a deficient number, since it is larger than the sum of its proper divisors (1).

81179291 is an equidigital number, since it uses as much as digits as its factorization.

81179291 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9072, while the sum is 38.

The square root of 81179291 is about 9009.9551053266. The cubic root of 81179291 is about 432.9938733317.

The spelling of 81179291 in words is "eighty-one million, one hundred seventy-nine thousand, two hundred ninety-one".