81304547 has 2 divisors, whose sum is σ = 81304548. Its totient is φ = 81304546.

The previous prime is 81304541. The next prime is 81304571. The reversal of 81304547 is 74540318.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81304547 - 2¹² = 81300451 is a prime.

It is a super-2 number, since 2×81304547² = 13220858725750418, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81304541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40652273 + 40652274.

It is an arithmetic number, because the mean of its divisors is an integer number (40652274).

Almost surely, 2^81304547 is an apocalyptic number.

81304547 is a deficient number, since it is larger than the sum of its proper divisors (1).

81304547 is an equidigital number, since it uses as much as digits as its factorization.

81304547 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 32.

The square root of 81304547 is about 9016.9034041627. The cubic root of 81304547 is about 433.2164555926.

The spelling of 81304547 in words is "eighty-one million, three hundred four thousand, five hundred forty-seven".