71220707561 has 2 divisors, whose sum is σ = 71220707562. Its totient is φ = 71220707560.

The previous prime is 71220707531. The next prime is 71220707573. The reversal of 71220707561 is 16570702217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 48248758336 + 22971949225 = 219656^2 + 151565^2 .

It is an emirp because it is prime and its reverse (16570702217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 71220707561 - 2¹⁰ = 71220706537 is a prime.

It is not a weakly prime, because it can be changed into another prime (71220707521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35610353780 + 35610353781.

It is an arithmetic number, because the mean of its divisors is an integer number (35610353781).

Almost surely, 2^71220707561 is an apocalyptic number.

It is an amenable number.

71220707561 is a deficient number, since it is larger than the sum of its proper divisors (1).

71220707561 is an equidigital number, since it uses as much as digits as its factorization.

71220707561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41160, while the sum is 38.

The spelling of 71220707561 in words is "seventy-one billion, two hundred twenty million, seven hundred seven thousand, five hundred sixty-one".