81577367 has 4 divisors (see below), whose sum is σ = 82726416. Its totient is φ = 80428320.

The previous prime is 81577361. The next prime is 81577381. The reversal of 81577367 is 76377518.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81577367 - 2¹⁰ = 81576343 is a prime.

It is a Duffinian number.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 574418 + ... + 574559.

It is an arithmetic number, because the mean of its divisors is an integer number (20681604).

Almost surely, 2^81577367 is an apocalyptic number.

81577367 is a deficient number, since it is larger than the sum of its proper divisors (1149049).

81577367 is a wasteful number, since it uses less digits than its factorization.

81577367 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1149048.

The product of its digits is 246960, while the sum is 44.

The square root of 81577367 is about 9032.0189880226. The cubic root of 81577367 is about 433.7004718285.

The spelling of 81577367 in words is "eighty-one million, five hundred seventy-seven thousand, three hundred sixty-seven".