81418933 has 16 divisors (see below), whose sum is σ = 91869120. Its totient is φ = 71698176.

The previous prime is 81418913. The next prime is 81418937. The reversal of 81418933 is 33981418.

It is a cyclic number.

It is not a de Polignac number, because 81418933 - 2¹⁷ = 81287861 is a prime.

It is a super-3 number, since 3×81418933³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81418892 and 81418901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81418937) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25291 + ... + 28327.

It is an arithmetic number, because the mean of its divisors is an integer number (5741820).

Almost surely, 2^81418933 is an apocalyptic number.

81418933 is a gapful number since it is divisible by the number (83) formed by its first and last digit.

It is an amenable number.

81418933 is a deficient number, since it is larger than the sum of its proper divisors (10450187).

81418933 is a wasteful number, since it uses less digits than its factorization.

81418933 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3156.

The product of its digits is 20736, while the sum is 37.

The square root of 81418933 is about 9023.2440397010. The cubic root of 81418933 is about 433.4195220409.

The spelling of 81418933 in words is "eighty-one million, four hundred eighteen thousand, nine hundred thirty-three".