71508121 has 2 divisors, whose sum is σ = 71508122. Its totient is φ = 71508120.

The previous prime is 71508089. The next prime is 71508139. The reversal of 71508121 is 12180517.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71318025 + 190096 = 8445^2 + 436^2 .

It is a cyclic number.

It is not a de Polignac number, because 71508121 - 2⁵ = 71508089 is a prime.

It is a super-2 number, since 2×71508121² = 10226822737901282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (71508721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35754060 + 35754061.

It is an arithmetic number, because the mean of its divisors is an integer number (35754061).

Almost surely, 2^71508121 is an apocalyptic number.

It is an amenable number.

71508121 is a deficient number, since it is larger than the sum of its proper divisors (1).

71508121 is an equidigital number, since it uses as much as digits as its factorization.

71508121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 560, while the sum is 25.

The square root of 71508121 is about 8456.2474538060. The cubic root of 71508121 is about 415.0672383434.

Adding to 71508121 its reverse (12180517), we get a palindrome (83688638).

The spelling of 71508121 in words is "seventy-one million, five hundred eight thousand, one hundred twenty-one".