81789039 has 6 divisors (see below), whose sum is σ = 118139736. Its totient is φ = 54526020.

The previous prime is 81789031. The next prime is 81789049. The reversal of 81789039 is 93098718.

It is not a de Polignac number, because 81789039 - 2³ = 81789031 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81788985 and 81789003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81789031) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4543827 + ... + 4543844.

It is an arithmetic number, because the mean of its divisors is an integer number (19689956).

Almost surely, 2^81789039 is an apocalyptic number.

81789039 is a deficient number, since it is larger than the sum of its proper divisors (36350697).

81789039 is a wasteful number, since it uses less digits than its factorization.

81789039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9087677 (or 9087674 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 45.

The square root of 81789039 is about 9043.7292639707. The cubic root of 81789039 is about 434.0752610743.

The spelling of 81789039 in words is "eighty-one million, seven hundred eighty-nine thousand, thirty-nine".