81502247 has 2 divisors, whose sum is σ = 81502248. Its totient is φ = 81502246.

The previous prime is 81502189. The next prime is 81502273. The reversal of 81502247 is 74220518.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81502247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81502297) 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, 40751123 + 40751124.

It is an arithmetic number, because the mean of its divisors is an integer number (40751124).

Almost surely, 2^81502247 is an apocalyptic number.

81502247 is a deficient number, since it is larger than the sum of its proper divisors (1).

81502247 is an equidigital number, since it uses as much as digits as its factorization.

81502247 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 81502247 is about 9027.8594915960. The cubic root of 81502247 is about 433.5673075045.

The spelling of 81502247 in words is "eighty-one million, five hundred two thousand, two hundred forty-seven".