81670441 has 2 divisors, whose sum is σ = 81670442. Its totient is φ = 81670440.

The previous prime is 81670367. The next prime is 81670481. The reversal of 81670441 is 14407618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76737600 + 4932841 = 8760^2 + 2221^2 .

It is a cyclic number.

It is not a de Polignac number, because 81670441 - 2¹³ = 81662249 is a prime.

It is not a weakly prime, because it can be changed into another prime (81670481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40835220 + 40835221.

It is an arithmetic number, because the mean of its divisors is an integer number (40835221).

Almost surely, 2^81670441 is an apocalyptic number.

It is an amenable number.

81670441 is a deficient number, since it is larger than the sum of its proper divisors (1).

81670441 is an equidigital number, since it uses as much as digits as its factorization.

81670441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81670441 is about 9037.1699663114. The cubic root of 81670441 is about 433.8653496504.

The spelling of 81670441 in words is "eighty-one million, six hundred seventy thousand, four hundred forty-one".