71255556 has 18 divisors (see below), whose sum is σ = 180118302. Its totient is φ = 23751840.

The previous prime is 71255497. The next prime is 71255557. The reversal of 71255556 is 65555217.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 70560000 + 695556 = 8400^2 + 834^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 1979321 = 71255556 / (7 + 1 + 2 + 5 + 5 + 5 + 5 + 6).

It is a self number, because there is not a number n which added to its sum of digits gives 71255556.

It is not an unprimeable number, because it can be changed into a prime (71255557) 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 5 ways as a sum of consecutive naturals, for example, 989625 + ... + 989696.

Almost surely, 2^71255556 is an apocalyptic number.

It is an amenable number.

71255556 is an abundant number, since it is smaller than the sum of its proper divisors (108862746).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

71255556 is a wasteful number, since it uses less digits than its factorization.

71255556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1979331 (or 1979326 counting only the distinct ones).

The product of its digits is 52500, while the sum is 36.

The square root of 71255556 is about 8441.3006106879. The cubic root of 71255556 is about 414.5779926508.

The spelling of 71255556 in words is "seventy-one million, two hundred fifty-five thousand, five hundred fifty-six".