71317840 has 40 divisors (see below), whose sum is σ = 180890208. Its totient is φ = 25933440.

The previous prime is 71317823. The next prime is 71317859. The reversal of 71317840 is 4871317.

71317840 = 263² + 264² + ... + 614².

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39642 + ... + 41401.

Almost surely, 2^71317840 is an apocalyptic number.

It is an amenable number.

71317840 is an abundant number, since it is smaller than the sum of its proper divisors (109572368).

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

71317840 is a wasteful number, since it uses less digits than its factorization.

71317840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81067 (or 81061 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 71317840 is about 8444.9890467661. The cubic root of 71317840 is about 414.6987507470.

The spelling of 71317840 in words is "seventy-one million, three hundred seventeen thousand, eight hundred forty".