71047021 has 6 divisors (see below), whose sum is σ = 71485610. Its totient is φ = 70609776.

The previous prime is 71047019. The next prime is 71047027. The reversal of 71047021 is 12074017.

It can be written as a sum of positive squares in 3 ways, for example, as 1990921 + 69056100 = 1411^2 + 8310^2 .

It is not a de Polignac number, because 71047021 - 2¹ = 71047019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71046983 and 71047001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71047027) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 127275 + ... + 127831.

Almost surely, 2^71047021 is an apocalyptic number.

It is an amenable number.

71047021 is a deficient number, since it is larger than the sum of its proper divisors (438589).

71047021 is an frugal number, since it uses more digits than its factorization.

71047021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1343 (or 786 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 71047021 is about 8428.9394943848. The cubic root of 71047021 is about 414.1731657521.

The spelling of 71047021 in words is "seventy-one million, forty-seven thousand, twenty-one".