81434887 has 2 divisors, whose sum is σ = 81434888. Its totient is φ = 81434886.

The previous prime is 81434867. The next prime is 81434921. The reversal of 81434887 is 78843418.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81434887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81434807) 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, 40717443 + 40717444.

It is an arithmetic number, because the mean of its divisors is an integer number (40717444).

Almost surely, 2^81434887 is an apocalyptic number.

81434887 is a deficient number, since it is larger than the sum of its proper divisors (1).

81434887 is an equidigital number, since it uses as much as digits as its factorization.

81434887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 172032, while the sum is 43.

The square root of 81434887 is about 9024.1280465206. The cubic root of 81434887 is about 433.4478296397.

The spelling of 81434887 in words is "eighty-one million, four hundred thirty-four thousand, eight hundred eighty-seven".