81469431 has 6 divisors (see below), whose sum is σ = 117678080. Its totient is φ = 54312948.

The previous prime is 81469411. The next prime is 81469433. The reversal of 81469431 is 13496418.

It is not a de Polignac number, because 81469431 - 2¹⁰ = 81468407 is a prime.

It is a super-2 number, since 2×81469431² = 13274536374927522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81469433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4526071 + ... + 4526088.

Almost surely, 2^81469431 is an apocalyptic number.

81469431 is a deficient number, since it is larger than the sum of its proper divisors (36208649).

81469431 is a wasteful number, since it uses less digits than its factorization.

81469431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9052165 (or 9052162 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 81469431 is about 9026.0418235238. The cubic root of 81469431 is about 433.5091092940.

The spelling of 81469431 in words is "eighty-one million, four hundred sixty-nine thousand, four hundred thirty-one".