81618695 has 4 divisors (see below), whose sum is σ = 97942440. Its totient is φ = 65294952.

The previous prime is 81618679. The next prime is 81618701. The reversal of 81618695 is 59681618.

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 81618695 - 2⁴ = 81618679 is a prime.

It is a super-2 number, since 2×81618695² = 13323222747006050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8161865 + ... + 8161874.

It is an arithmetic number, because the mean of its divisors is an integer number (24485610).

Almost surely, 2^81618695 is an apocalyptic number.

81618695 is a deficient number, since it is larger than the sum of its proper divisors (16323745).

81618695 is a wasteful number, since it uses less digits than its factorization.

81618695 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16323744.

The product of its digits is 103680, while the sum is 44.

The square root of 81618695 is about 9034.3065588898. The cubic root of 81618695 is about 433.7736986224.

The spelling of 81618695 in words is "eighty-one million, six hundred eighteen thousand, six hundred ninety-five".