71307520 has 144 divisors (see below), whose sum is σ = 188742960. Its totient is φ = 25690112.

The previous prime is 71307493. The next prime is 71307527. The reversal of 71307520 is 2570317.

It can be written as a sum of positive squares in 8 ways, for example, as 3936256 + 67371264 = 1984^2 + 8208^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71307527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 630984 + ... + 631096.

It is an arithmetic number, because the mean of its divisors is an integer number (1310715).

Almost surely, 2^71307520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 71307520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94371480).

71307520 is an abundant number, since it is smaller than the sum of its proper divisors (117435440).

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

71307520 is a wasteful number, since it uses less digits than its factorization.

71307520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 1470, while the sum is 25.

The square root of 71307520 is about 8444.3780114346. The cubic root of 71307520 is about 414.6787468809.

Adding to 71307520 its reverse (2570317), we get a palindrome (73877837).

The spelling of 71307520 in words is "seventy-one million, three hundred seven thousand, five hundred twenty".