81434109 has 4 divisors (see below), whose sum is σ = 108578816. Its totient is φ = 54289404.

The previous prime is 81434107. The next prime is 81434113. The reversal of 81434109 is 90143418.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 81434109 - 2¹ = 81434107 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81434107) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13572349 + ... + 13572354.

It is an arithmetic number, because the mean of its divisors is an integer number (27144704).

Almost surely, 2^81434109 is an apocalyptic number.

It is an amenable number.

81434109 is a deficient number, since it is larger than the sum of its proper divisors (27144707).

81434109 is a wasteful number, since it uses less digits than its factorization.

81434109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27144706.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 81434109 is about 9024.0849397598. The cubic root of 81434109 is about 433.4464492997.

The spelling of 81434109 in words is "eighty-one million, four hundred thirty-four thousand, one hundred nine".