81785733 has 4 divisors (see below), whose sum is σ = 109047648. Its totient is φ = 54523820.

The previous prime is 81785701. The next prime is 81785773. The reversal of 81785733 is 33758718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81785733 - 2⁵ = 81785701 is a prime.

It is a super-2 number, since 2×81785733² = 13377812244694578, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81785773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13630953 + ... + 13630958.

It is an arithmetic number, because the mean of its divisors is an integer number (27261912).

Almost surely, 2^81785733 is an apocalyptic number.

It is an amenable number.

81785733 is a deficient number, since it is larger than the sum of its proper divisors (27261915).

81785733 is a wasteful number, since it uses less digits than its factorization.

81785733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27261914.

The product of its digits is 141120, while the sum is 42.

The square root of 81785733 is about 9043.5464835428. The cubic root of 81785733 is about 434.0694124009.

The spelling of 81785733 in words is "eighty-one million, seven hundred eighty-five thousand, seven hundred thirty-three".