71230021 has 4 divisors (see below), whose sum is σ = 71338444. Its totient is φ = 71121600.

The previous prime is 71230001. The next prime is 71230043. The reversal of 71230021 is 12003217.

It is a happy number.

71230021 is nontrivially palindromic in base 14.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12003217 = 23 ⋅521879.

It can be written as a sum of positive squares in 2 ways, for example, as 42393121 + 28836900 = 6511^2 + 5370^2 .

It is a cyclic number.

It is not a de Polignac number, because 71230021 - 2⁵ = 71229989 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71229977 and 71230004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71230001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53220 + ... + 54541.

It is an arithmetic number, because the mean of its divisors is an integer number (17834611).

Almost surely, 2^71230021 is an apocalyptic number.

It is an amenable number.

71230021 is a deficient number, since it is larger than the sum of its proper divisors (108423).

71230021 is a wasteful number, since it uses less digits than its factorization.

71230021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108422.

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

The square root of 71230021 is about 8439.7879712704. The cubic root of 71230021 is about 414.5284642844.

Adding to 71230021 its reverse (12003217), we get a palindrome (83233238).

The spelling of 71230021 in words is "seventy-one million, two hundred thirty thousand, twenty-one".