71307220 has 24 divisors (see below), whose sum is σ = 150338664. Its totient is φ = 28409856.

The previous prime is 71307211. The next prime is 71307221. The reversal of 71307220 is 2270317.

It can be written as a sum of positive squares in 4 ways, for example, as 25040016 + 46267204 = 5004^2 + 6802^2 .

It is a junction number, because it is equal to n+sod(n) for n = 71307191 and 71307200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71307221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1797 + ... + 12076.

It is an arithmetic number, because the mean of its divisors is an integer number (6264111).

Almost surely, 2^71307220 is an apocalyptic number.

It is an amenable number.

71307220 is an abundant number, since it is smaller than the sum of its proper divisors (79031444).

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

71307220 is a wasteful number, since it uses less digits than its factorization.

71307220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14139 (or 14137 counting only the distinct ones).

The product of its (nonzero) digits is 588, while the sum is 22.

The square root of 71307220 is about 8444.3602481183. The cubic root of 71307220 is about 414.6781653443.

Adding to 71307220 its reverse (2270317), we get a palindrome (73577537).

The spelling of 71307220 in words is "seventy-one million, three hundred seven thousand, two hundred twenty".