81429205 has 32 divisors (see below), whose sum is σ = 116742528. Its totient is φ = 53740800.

The previous prime is 81429203. The next prime is 81429211. The reversal of 81429205 is 50292418.

It is not a de Polignac number, because 81429205 - 2¹ = 81429203 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81429203) 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 in 31 ways as a sum of consecutive naturals, for example, 42682 + ... + 44548.

It is an arithmetic number, because the mean of its divisors is an integer number (3648204).

Almost surely, 2^81429205 is an apocalyptic number.

It is an amenable number.

81429205 is a deficient number, since it is larger than the sum of its proper divisors (35313323).

81429205 is a wasteful number, since it uses less digits than its factorization.

81429205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1957.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 81429205 is about 9023.8132183684. The cubic root of 81429205 is about 433.4377483427.

The spelling of 81429205 in words is "eighty-one million, four hundred twenty-nine thousand, two hundred five".