81360947 has 2 divisors, whose sum is σ = 81360948. Its totient is φ = 81360946.

The previous prime is 81360943. The next prime is 81360949. The reversal of 81360947 is 74906318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81360947 - 2² = 81360943 is a prime.

Together with 81360949, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81360947.

It is not a weakly prime, because it can be changed into another prime (81360943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40680473 + 40680474.

It is an arithmetic number, because the mean of its divisors is an integer number (40680474).

Almost surely, 2^81360947 is an apocalyptic number.

81360947 is a deficient number, since it is larger than the sum of its proper divisors (1).

81360947 is an equidigital number, since it uses as much as digits as its factorization.

81360947 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 81360947 is about 9020.0303214568. The cubic root of 81360947 is about 433.3166048112.

The spelling of 81360947 in words is "eighty-one million, three hundred sixty thousand, nine hundred forty-seven".