81577368 has 120 divisors (see below), whose sum is σ = 237902940. Its totient is φ = 26114400.

The previous prime is 81577361. The next prime is 81577381. The reversal of 81577368 is 86377518.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81577361) 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 29 ways as a sum of consecutive naturals, for example, 622663 + ... + 622793.

Almost surely, 2^81577368 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81577368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118951470).

81577368 is an abundant number, since it is smaller than the sum of its proper divisors (156325572).

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

81577368 is a wasteful number, since it uses less digits than its factorization.

81577368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 167 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 81577368 is about 9032.0190433812. The cubic root of 81577368 is about 433.7004736006.

The spelling of 81577368 in words is "eighty-one million, five hundred seventy-seven thousand, three hundred sixty-eight".