81670041 has 12 divisors (see below), whose sum is σ = 118046500. Its totient is φ = 54410400.

The previous prime is 81670031. The next prime is 81670051. The reversal of 81670041 is 14007618.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81670031) and next prime (81670051).

It can be written as a sum of positive squares in 2 ways, for example, as 13111641 + 68558400 = 3621^2 + 8280^2 .

It is not a de Polignac number, because 81670041 - 2⁶ = 81669977 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81669987 and 81670014.

It is not an unprimeable number, because it can be changed into a prime (81670031) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23091 + ... + 26391.

Almost surely, 2^81670041 is an apocalyptic number.

It is an amenable number.

81670041 is a deficient number, since it is larger than the sum of its proper divisors (36376459).

81670041 is a wasteful number, since it uses less digits than its factorization.

81670041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6056 (or 6053 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 81670041 is about 9037.1478354622. The cubic root of 81670041 is about 433.8646413304.

Adding to 81670041 its reverse (14007618), we get a palindrome (95677659).

The spelling of 81670041 in words is "eighty-one million, six hundred seventy thousand, forty-one".