81466757 has 2 divisors, whose sum is σ = 81466758. Its totient is φ = 81466756.

The previous prime is 81466753. The next prime is 81466769. The reversal of 81466757 is 75766418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50708641 + 30758116 = 7121^2 + 5546^2 .

It is a cyclic number.

It is not a de Polignac number, because 81466757 - 2² = 81466753 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81466751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40733378 + 40733379.

It is an arithmetic number, because the mean of its divisors is an integer number (40733379).

Almost surely, 2^81466757 is an apocalyptic number.

It is an amenable number.

81466757 is a deficient number, since it is larger than the sum of its proper divisors (1).

81466757 is an equidigital number, since it uses as much as digits as its factorization.

81466757 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 282240, while the sum is 44.

The square root of 81466757 is about 9025.8936953634. The cubic root of 81466757 is about 433.5043663451.

The spelling of 81466757 in words is "eighty-one million, four hundred sixty-six thousand, seven hundred fifty-seven".