71078211221 has 2 divisors, whose sum is σ = 71078211222. Its totient is φ = 71078211220.

The previous prime is 71078211181. The next prime is 71078211227. The reversal of 71078211221 is 12211287017.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 47825316100 + 23252895121 = 218690^2 + 152489^2 .

It is a cyclic number.

It is not a de Polignac number, because 71078211221 - 2⁶ = 71078211157 is a prime.

It is a super-2 number, since 2×71078211221² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (71078211227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35539105610 + 35539105611.

It is an arithmetic number, because the mean of its divisors is an integer number (35539105611).

Almost surely, 2^71078211221 is an apocalyptic number.

It is an amenable number.

71078211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

71078211221 is an equidigital number, since it uses as much as digits as its factorization.

71078211221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3136, while the sum is 32.

Adding to 71078211221 its reverse (12211287017), we get a palindrome (83289498238).

The spelling of 71078211221 in words is "seventy-one billion, seventy-eight million, two hundred eleven thousand, two hundred twenty-one".