81670789 has 8 divisors (see below), whose sum is σ = 83267360. Its totient is φ = 80085456.

The previous prime is 81670781. The next prime is 81670801. The reversal of 81670789 is 98707618.

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 81670789 - 2³ = 81670781 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81670781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12682 + ... + 18004.

It is an arithmetic number, because the mean of its divisors is an integer number (10408420).

Almost surely, 2^81670789 is an apocalyptic number.

It is an amenable number.

81670789 is a deficient number, since it is larger than the sum of its proper divisors (1596571).

81670789 is a wasteful number, since it uses less digits than its factorization.

81670789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5619.

The product of its (nonzero) digits is 169344, while the sum is 46.

The square root of 81670789 is about 9037.1892201060. The cubic root of 81670789 is about 433.8659658869.

The spelling of 81670789 in words is "eighty-one million, six hundred seventy thousand, seven hundred eighty-nine".