81618677 has 4 divisors (see below), whose sum is σ = 93278496. Its totient is φ = 69958860.

The previous prime is 81618643. The next prime is 81618679. The reversal of 81618677 is 77681618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81618677 - 2²⁰ = 80570101 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 (81618679) 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 3 ways as a sum of consecutive naturals, for example, 5829899 + ... + 5829912.

It is an arithmetic number, because the mean of its divisors is an integer number (23319624).

Almost surely, 2^81618677 is an apocalyptic number.

It is an amenable number.

81618677 is a deficient number, since it is larger than the sum of its proper divisors (11659819).

81618677 is a wasteful number, since it uses less digits than its factorization.

81618677 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11659818.

The product of its digits is 112896, while the sum is 44.

The square root of 81618677 is about 9034.3055626872. The cubic root of 81618677 is about 433.7736667346.

The spelling of 81618677 in words is "eighty-one million, six hundred eighteen thousand, six hundred seventy-seven".