81443497 has 2 divisors, whose sum is σ = 81443498. Its totient is φ = 81443496.

The previous prime is 81443477. The next prime is 81443561. The reversal of 81443497 is 79434418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49056016 + 32387481 = 7004^2 + 5691^2 .

It is a cyclic number.

It is not a de Polignac number, because 81443497 - 2¹⁵ = 81410729 is a prime.

It is not a weakly prime, because it can be changed into another prime (81443477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40721748 + 40721749.

It is an arithmetic number, because the mean of its divisors is an integer number (40721749).

Almost surely, 2^81443497 is an apocalyptic number.

It is an amenable number.

81443497 is a deficient number, since it is larger than the sum of its proper divisors (1).

81443497 is an equidigital number, since it uses as much as digits as its factorization.

81443497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 40.

The square root of 81443497 is about 9024.6050883127. The cubic root of 81443497 is about 433.4631050514.

The spelling of 81443497 in words is "eighty-one million, four hundred forty-three thousand, four hundred ninety-seven".