80781138 has 40 divisors (see below), whose sum is σ = 185915532. Its totient is φ = 26197344.

The previous prime is 80781131. The next prime is 80781157. The reversal of 80781138 is 83118708.

It can be written as a sum of positive squares in 2 ways, for example, as 72641529 + 8139609 = 8523^2 + 2853^2 .

It is not an unprimeable number, because it can be changed into a prime (80781131) 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 19 ways as a sum of consecutive naturals, for example, 745 + ... + 12732.

Almost surely, 2^80781138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 80781138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92957766).

80781138 is an abundant number, since it is smaller than the sum of its proper divisors (105134394).

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

80781138 is a wasteful number, since it uses less digits than its factorization.

80781138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13528 (or 13519 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 80781138 is about 8987.8327754804. The cubic root of 80781138 is about 432.2848237445.

It can be divided in two parts, 8078 and 1138, that added together give a square (9216 = 96²).

The spelling of 80781138 in words is "eighty million, seven hundred eighty-one thousand, one hundred thirty-eight".