71255557 has 2 divisors, whose sum is σ = 71255558. Its totient is φ = 71255556.

The previous prime is 71255497. The next prime is 71255573. The reversal of 71255557 is 75555217.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71132356 + 123201 = 8434^2 + 351^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71255557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71253557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35627778 + 35627779.

It is an arithmetic number, because the mean of its divisors is an integer number (35627779).

Almost surely, 2^71255557 is an apocalyptic number.

It is an amenable number.

71255557 is a deficient number, since it is larger than the sum of its proper divisors (1).

71255557 is an equidigital number, since it uses as much as digits as its factorization.

71255557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61250, while the sum is 37.

The square root of 71255557 is about 8441.3006699205. The cubic root of 71255557 is about 414.5779945902.

The spelling of 71255557 in words is "seventy-one million, two hundred fifty-five thousand, five hundred fifty-seven".