70205256581 has 2 divisors, whose sum is σ = 70205256582. Its totient is φ = 70205256580.

The previous prime is 70205256497. The next prime is 70205256587. The reversal of 70205256581 is 18565250207.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40686924100 + 29518332481 = 201710^2 + 171809^2 .

It is a cyclic number.

It is not a de Polignac number, because 70205256581 - 2¹⁰ = 70205255557 is a prime.

It is a super-2 number, since 2×70205256581² (a number of 22 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (70205256587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 35102628290 + 35102628291.

It is an arithmetic number, because the mean of its divisors is an integer number (35102628291).

Almost surely, 2^70205256581 is an apocalyptic number.

It is an amenable number.

70205256581 is a deficient number, since it is larger than the sum of its proper divisors (1).

70205256581 is an equidigital number, since it uses as much as digits as its factorization.

70205256581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168000, while the sum is 41.

The spelling of 70205256581 in words is "seventy billion, two hundred five million, two hundred fifty-six thousand, five hundred eighty-one".