81165479 has 2 divisors, whose sum is σ = 81165480. Its totient is φ = 81165478.

The previous prime is 81165449. The next prime is 81165481. The reversal of 81165479 is 97456118.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81165479 is a prime.

Together with 81165481, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81165449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40582739 + 40582740.

It is an arithmetic number, because the mean of its divisors is an integer number (40582740).

Almost surely, 2^81165479 is an apocalyptic number.

81165479 is a deficient number, since it is larger than the sum of its proper divisors (1).

81165479 is an equidigital number, since it uses as much as digits as its factorization.

81165479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 41.

The square root of 81165479 is about 9009.1885872147. The cubic root of 81165479 is about 432.9693151366.

The spelling of 81165479 in words is "eighty-one million, one hundred sixty-five thousand, four hundred seventy-nine".