71020121 has 2 divisors, whose sum is σ = 71020122. Its totient is φ = 71020120.

The previous prime is 71020091. The next prime is 71020123. The reversal of 71020121 is 12102017.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 64963600 + 6056521 = 8060^2 + 2461^2 .

It is an emirp because it is prime and its reverse (12102017) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71020121 is a prime.

Together with 71020123, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 71020096 and 71020105.

It is not a weakly prime, because it can be changed into another prime (71020123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35510060 + 35510061.

It is an arithmetic number, because the mean of its divisors is an integer number (35510061).

Almost surely, 2^71020121 is an apocalyptic number.

It is an amenable number.

71020121 is a deficient number, since it is larger than the sum of its proper divisors (1).

71020121 is an equidigital number, since it uses as much as digits as its factorization.

71020121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 71020121 is about 8427.3436502851. The cubic root of 71020121 is about 414.1208873952.

Adding to 71020121 its reverse (12102017), we get a palindrome (83122138).

The spelling of 71020121 in words is "seventy-one million, twenty thousand, one hundred twenty-one".