81144403 has 2 divisors, whose sum is σ = 81144404. Its totient is φ = 81144402.

The previous prime is 81144389. The next prime is 81144443. The reversal of 81144403 is 30444118.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81144403 is a prime.

It is not a weakly prime, because it can be changed into another prime (81144443) 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, 40572201 + 40572202.

It is an arithmetic number, because the mean of its divisors is an integer number (40572202).

Almost surely, 2^81144403 is an apocalyptic number.

81144403 is a deficient number, since it is larger than the sum of its proper divisors (1).

81144403 is an equidigital number, since it uses as much as digits as its factorization.

81144403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 81144403 is about 9008.0188165878. The cubic root of 81144403 is about 432.9318359383.

It can be divided in two parts, 8 and 1144403, that added together give a palindrome (1144411).

The spelling of 81144403 in words is "eighty-one million, one hundred forty-four thousand, four hundred three".