81249941 has 2 divisors, whose sum is σ = 81249942. Its totient is φ = 81249940.

The previous prime is 81249937. The next prime is 81249943. The reversal of 81249941 is 14994218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 67404100 + 13845841 = 8210^2 + 3721^2 .

It is a cyclic number.

It is not a de Polignac number, because 81249941 - 2² = 81249937 is a prime.

Together with 81249943, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_4738277 and since 81249941 and 4738277 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 81249895 and 81249904.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81249943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40624970 + 40624971.

It is an arithmetic number, because the mean of its divisors is an integer number (40624971).

Almost surely, 2^81249941 is an apocalyptic number.

It is an amenable number.

81249941 is a deficient number, since it is larger than the sum of its proper divisors (1).

81249941 is an equidigital number, since it uses as much as digits as its factorization.

81249941 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20736, while the sum is 38.

The square root of 81249941 is about 9013.8749159282. The cubic root of 81249941 is about 433.1194478333.

The spelling of 81249941 in words is "eighty-one million, two hundred forty-nine thousand, nine hundred forty-one".