81445037 has 2 divisors, whose sum is σ = 81445038. Its totient is φ = 81445036.

The previous prime is 81445033. The next prime is 81445043. The reversal of 81445037 is 73054418.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79673476 + 1771561 = 8926^2 + 1331^2 .

It is a cyclic number.

It is not a de Polignac number, because 81445037 - 2² = 81445033 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81444994 and 81445012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81445033) 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, 40722518 + 40722519.

It is an arithmetic number, because the mean of its divisors is an integer number (40722519).

Almost surely, 2^81445037 is an apocalyptic number.

It is an amenable number.

81445037 is a deficient number, since it is larger than the sum of its proper divisors (1).

81445037 is an equidigital number, since it uses as much as digits as its factorization.

81445037 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 81445037 is about 9024.6904102024. The cubic root of 81445037 is about 433.4658371254.

The spelling of 81445037 in words is "eighty-one million, four hundred forty-five thousand, thirty-seven".