81379188 has 48 divisors (see below), whose sum is σ = 230166720. Its totient is φ = 24660000.

The previous prime is 81379183. The next prime is 81379201. The reversal of 81379188 is 88197318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81379183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33063 + ... + 35438.

It is an arithmetic number, because the mean of its divisors is an integer number (4795140).

Almost surely, 2^81379188 is an apocalyptic number.

It is an amenable number.

81379188 is an abundant number, since it is smaller than the sum of its proper divisors (148787532).

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

81379188 is a wasteful number, since it uses less digits than its factorization.

81379188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68525 (or 68517 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 81379188 is about 9021.0414032971. The cubic root of 81379188 is about 433.3489853649.

The spelling of 81379188 in words is "eighty-one million, three hundred seventy-nine thousand, one hundred eighty-eight".