81510203 has 2 divisors, whose sum is σ = 81510204. Its totient is φ = 81510202.

The previous prime is 81510197. The next prime is 81510227. The reversal of 81510203 is 30201518.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81510203 - 2¹² = 81506107 is a prime.

It is not a weakly prime, because it can be changed into another prime (81510263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40755101 + 40755102.

It is an arithmetic number, because the mean of its divisors is an integer number (40755102).

Almost surely, 2^81510203 is an apocalyptic number.

81510203 is a deficient number, since it is larger than the sum of its proper divisors (1).

81510203 is an equidigital number, since it uses as much as digits as its factorization.

81510203 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 81510203 is about 9028.3001168548. The cubic root of 81510203 is about 433.5814148835.

The spelling of 81510203 in words is "eighty-one million, five hundred ten thousand, two hundred three".