81434693 has 4 divisors (see below), whose sum is σ = 82155468. Its totient is φ = 80713920.

The previous prime is 81434677. The next prime is 81434699. The reversal of 81434693 is 39643418.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1117249 + 80317444 = 1057^2 + 8962^2 .

It is a cyclic number.

It is not a de Polignac number, because 81434693 - 2⁴ = 81434677 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 (81434699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360218 + ... + 360443.

It is an arithmetic number, because the mean of its divisors is an integer number (20538867).

Almost surely, 2^81434693 is an apocalyptic number.

It is an amenable number.

81434693 is a deficient number, since it is larger than the sum of its proper divisors (720775).

81434693 is a wasteful number, since it uses less digits than its factorization.

81434693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720774.

The product of its digits is 62208, while the sum is 38.

The square root of 81434693 is about 9024.1172975533. The cubic root of 81434693 is about 433.4474854426.

The spelling of 81434693 in words is "eighty-one million, four hundred thirty-four thousand, six hundred ninety-three".