71005780 has 12 divisors (see below), whose sum is σ = 149112180. Its totient is φ = 28402304.

The previous prime is 71005763. The next prime is 71005783. The reversal of 71005780 is 8750017.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 21641104 + 49364676 = 4652^2 + 7026^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71005783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1775125 + ... + 1775164.

It is an arithmetic number, because the mean of its divisors is an integer number (12426015).

Almost surely, 2^71005780 is an apocalyptic number.

It is an amenable number.

71005780 is an abundant number, since it is smaller than the sum of its proper divisors (78106400).

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

71005780 is a wasteful number, since it uses less digits than its factorization.

71005780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3550298 (or 3550296 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 28.

The square root of 71005780 is about 8426.4927460955. The cubic root of 71005780 is about 414.0930112226.

Adding to 71005780 its reverse (8750017), we get a palindrome (79755797).

It can be divided in two parts, 7100 and 5780, that added together give a triangular number (12880 = T₁₆₀).

The spelling of 71005780 in words is "seventy-one million, five thousand, seven hundred eighty".