81905367 has 8 divisors (see below), whose sum is σ = 112973040. Its totient is φ = 52720640.

The previous prime is 81905359. The next prime is 81905377. The reversal of 81905367 is 76350918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81905367 - 2³ = 81905359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81905357) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 470634 + ... + 470807.

It is an arithmetic number, because the mean of its divisors is an integer number (14121630).

Almost surely, 2^81905367 is an apocalyptic number.

81905367 is a gapful number since it is divisible by the number (87) formed by its first and last digit.

81905367 is a deficient number, since it is larger than the sum of its proper divisors (31067673).

81905367 is a wasteful number, since it uses less digits than its factorization.

81905367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 941473.

The product of its (nonzero) digits is 45360, while the sum is 39.

The square root of 81905367 is about 9050.1583964039. The cubic root of 81905367 is about 434.2809576928.

The spelling of 81905367 in words is "eighty-one million, nine hundred five thousand, three hundred sixty-seven".