81386433 has 12 divisors (see below), whose sum is σ = 118338688. Its totient is φ = 53897400.

The previous prime is 81386407. The next prime is 81386471. The reversal of 81386433 is 33468318.

It is a happy number.

81386433 is a `hidden beast` number, since 8 + 1 + 3 + 8 + 643 + 3 = 666.

It is not a de Polignac number, because 81386433 - 2⁹ = 81385921 is a prime.

It is a super-3 number, since 3×81386433³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81386483) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28585 + ... + 31302.

Almost surely, 2^81386433 is an apocalyptic number.

It is an amenable number.

81386433 is a deficient number, since it is larger than the sum of its proper divisors (36952255).

81386433 is a wasteful number, since it uses less digits than its factorization.

81386433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60044 (or 60041 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 81386433 is about 9021.4429555365. The cubic root of 81386433 is about 433.3618450011.

The spelling of 81386433 in words is "eighty-one million, three hundred eighty-six thousand, four hundred thirty-three".