81174257 has 2 divisors, whose sum is σ = 81174258. Its totient is φ = 81174256.

The previous prime is 81174241. The next prime is 81174349. The reversal of 81174257 is 75247118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67749361 + 13424896 = 8231^2 + 3664^2 .

It is a cyclic number.

It is not a de Polignac number, because 81174257 - 2⁴ = 81174241 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81174557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40587128 + 40587129.

It is an arithmetic number, because the mean of its divisors is an integer number (40587129).

Almost surely, 2^81174257 is an apocalyptic number.

It is an amenable number.

81174257 is a deficient number, since it is larger than the sum of its proper divisors (1).

81174257 is an equidigital number, since it uses as much as digits as its factorization.

81174257 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15680, while the sum is 35.

The square root of 81174257 is about 9009.6757433328. The cubic root of 81174257 is about 432.9849230350.

The spelling of 81174257 in words is "eighty-one million, one hundred seventy-four thousand, two hundred fifty-seven".