81677231 has 16 divisors (see below), whose sum is σ = 89101440. Its totient is φ = 74580480.

The previous prime is 81677227. The next prime is 81677237. The reversal of 81677231 is 13277618.

It is a cyclic number.

It is not a de Polignac number, because 81677231 - 2² = 81677227 is a prime.

It is a super-2 number, since 2×81677231² = 13342340127654722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81677191 and 81677200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81677237) 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 15 ways as a sum of consecutive naturals, for example, 81425 + ... + 82421.

It is an arithmetic number, because the mean of its divisors is an integer number (5568840).

Almost surely, 2^81677231 is an apocalyptic number.

81677231 is a deficient number, since it is larger than the sum of its proper divisors (7424209).

81677231 is a wasteful number, since it uses less digits than its factorization.

81677231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1154.

The product of its digits is 14112, while the sum is 35.

The square root of 81677231 is about 9037.5456292071. The cubic root of 81677231 is about 433.8773730298.

The spelling of 81677231 in words is "eighty-one million, six hundred seventy-seven thousand, two hundred thirty-one".