71312020 has 24 divisors (see below), whose sum is σ = 161275464. Its totient is φ = 26330496.

The previous prime is 71311993. The next prime is 71312039. The reversal of 71312020 is 2021317.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 145924 + 71166096 = 382^2 + 8436^2 .

It is a junction number, because it is equal to n+sod(n) for n = 71311985 and 71312003.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 136879 + ... + 137398.

It is an arithmetic number, because the mean of its divisors is an integer number (6719811).

Almost surely, 2^71312020 is an apocalyptic number.

It is an amenable number.

71312020 is an abundant number, since it is smaller than the sum of its proper divisors (89963444).

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

71312020 is a wasteful number, since it uses less digits than its factorization.

71312020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 274299 (or 274297 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 71312020 is about 8444.6444566956. The cubic root of 71312020 is about 414.6874697342.

Adding to 71312020 its reverse (2021317), we get a palindrome (73333337).

The spelling of 71312020 in words is "seventy-one million, three hundred twelve thousand, twenty".