705601721021 has 2 divisors, whose sum is σ = 705601721022. Its totient is φ = 705601721020.

The previous prime is 705601721003. The next prime is 705601721051. The reversal of 705601721021 is 120127106507.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 703728043225 + 1873677796 = 838885^2 + 43286^2 .

It is a cyclic number.

It is not a de Polignac number, because 705601721021 - 2²⁶ = 705534612157 is a prime.

It is a super-2 number, since 2×705601721021² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (705601721051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 352800860510 + 352800860511.

It is an arithmetic number, because the mean of its divisors is an integer number (352800860511).

Almost surely, 2^705601721021 is an apocalyptic number.

It is an amenable number.

705601721021 is a deficient number, since it is larger than the sum of its proper divisors (1).

705601721021 is an equidigital number, since it uses as much as digits as its factorization.

705601721021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5880, while the sum is 32.

Adding to 705601721021 its reverse (120127106507), we get a palindrome (825728827528).

The spelling of 705601721021 in words is "seven hundred five billion, six hundred one million, seven hundred twenty-one thousand, twenty-one".