81789078 has 16 divisors (see below), whose sum is σ = 186946560. Its totient is φ = 23368296.

The previous prime is 81789073. The next prime is 81789079. The reversal of 81789078 is 87098718.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81789073) 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, 973638 + ... + 973721.

It is an arithmetic number, because the mean of its divisors is an integer number (11684160).

Almost surely, 2^81789078 is an apocalyptic number.

81789078 is an abundant number, since it is smaller than the sum of its proper divisors (105157482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81789078 is a wasteful number, since it uses less digits than its factorization.

81789078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1947371.

The product of its (nonzero) digits is 225792, while the sum is 48.

The square root of 81789078 is about 9043.7314201606. The cubic root of 81789078 is about 434.0753300686.

The spelling of 81789078 in words is "eighty-one million, seven hundred eighty-nine thousand, seventy-eight".