71540257 has 4 divisors (see below), whose sum is σ = 71624980. Its totient is φ = 71455536.

The previous prime is 71540237. The next prime is 71540299. The reversal of 71540257 is 75204517.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6270016 + 65270241 = 2504^2 + 8079^2 .

It is a cyclic number.

It is not a de Polignac number, because 71540257 - 2¹⁹ = 71015969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71540207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41082 + ... + 42787.

It is an arithmetic number, because the mean of its divisors is an integer number (17906245).

Almost surely, 2^71540257 is an apocalyptic number.

It is an amenable number.

71540257 is a deficient number, since it is larger than the sum of its proper divisors (84723).

71540257 is an equidigital number, since it uses as much as digits as its factorization.

71540257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84722.

The product of its (nonzero) digits is 9800, while the sum is 31.

The square root of 71540257 is about 8458.1473739821. The cubic root of 71540257 is about 415.1294065882.

The spelling of 71540257 in words is "seventy-one million, five hundred forty thousand, two hundred fifty-seven".