81676745 has 4 divisors (see below), whose sum is σ = 98012100. Its totient is φ = 65341392.

The previous prime is 81676729. The next prime is 81676747. The reversal of 81676745 is 54767618.

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

It can be written as a sum of positive squares in 2 ways, for example, as 42876304 + 38800441 = 6548^2 + 6229^2 .

It is a cyclic number.

It is not a de Polignac number, because 81676745 - 2⁴ = 81676729 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 81676696 and 81676705.

It is not an unprimeable number, because it can be changed into a prime (81676747) 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, 8167670 + ... + 8167679.

It is an arithmetic number, because the mean of its divisors is an integer number (24503025).

Almost surely, 2^81676745 is an apocalyptic number.

It is an amenable number.

81676745 is a deficient number, since it is larger than the sum of its proper divisors (16335355).

81676745 is a wasteful number, since it uses less digits than its factorization.

81676745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16335354.

The product of its digits is 282240, while the sum is 44.

The square root of 81676745 is about 9037.5187413360. The cubic root of 81676745 is about 433.8765124683.

The spelling of 81676745 in words is "eighty-one million, six hundred seventy-six thousand, seven hundred forty-five".