81790869 has 8 divisors (see below), whose sum is σ = 110020032. Its totient is φ = 54044480.

The previous prime is 81790867. The next prime is 81790873. The reversal of 81790869 is 96809718.

It is a happy number.

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 81790869 - 2¹ = 81790867 is a prime.

It is a super-2 number, since 2×81790869² = 13379492503550322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81790861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 120297 + ... + 120974.

It is an arithmetic number, because the mean of its divisors is an integer number (13752504).

Almost surely, 2^81790869 is an apocalyptic number.

It is an amenable number.

81790869 is a deficient number, since it is larger than the sum of its proper divisors (28229163).

81790869 is a wasteful number, since it uses less digits than its factorization.

81790869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241387.

The product of its (nonzero) digits is 217728, while the sum is 48.

The square root of 81790869 is about 9043.8304384813. The cubic root of 81790869 is about 434.0784984755.

The spelling of 81790869 in words is "eighty-one million, seven hundred ninety thousand, eight hundred sixty-nine".