81274993 has 2 divisors, whose sum is σ = 81274994. Its totient is φ = 81274992.

The previous prime is 81274981. The next prime is 81275009. The reversal of 81274993 is 39947218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75481344 + 5793649 = 8688^2 + 2407^2 .

It is a cyclic number.

It is not a de Polignac number, because 81274993 - 2⁵ = 81274961 is a prime.

It is not a weakly prime, because it can be changed into another prime (81274933) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40637496 + 40637497.

It is an arithmetic number, because the mean of its divisors is an integer number (40637497).

Almost surely, 2^81274993 is an apocalyptic number.

It is an amenable number.

81274993 is a deficient number, since it is larger than the sum of its proper divisors (1).

81274993 is an equidigital number, since it uses as much as digits as its factorization.

81274993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 43.

The square root of 81274993 is about 9015.2644442634. The cubic root of 81274993 is about 433.1639581975.

The spelling of 81274993 in words is "eighty-one million, two hundred seventy-four thousand, nine hundred ninety-three".