81580765 has 8 divisors (see below), whose sum is σ = 111882240. Its totient is φ = 55941072.

The previous prime is 81580757. The next prime is 81580769. The reversal of 81580765 is 56708518.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81580765 - 2³ = 81580757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81580769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1165405 + ... + 1165474.

It is an arithmetic number, because the mean of its divisors is an integer number (13985280).

Almost surely, 2^81580765 is an apocalyptic number.

It is an amenable number.

81580765 is a deficient number, since it is larger than the sum of its proper divisors (30301475).

81580765 is a wasteful number, since it uses less digits than its factorization.

81580765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2330891.

The product of its (nonzero) digits is 67200, while the sum is 40.

The square root of 81580765 is about 9032.2070946143. The cubic root of 81580765 is about 433.7064934895.

The spelling of 81580765 in words is "eighty-one million, five hundred eighty thousand, seven hundred sixty-five".