1722957351721 has 2 divisors, whose sum is σ = 1722957351722. Its totient is φ = 1722957351720.

The previous prime is 1722957351683. The next prime is 1722957351727. The reversal of 1722957351721 is 1271537592271.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1408921520400 + 314035831321 = 1186980^2 + 560389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1722957351721 is a prime.

It is not a weakly prime, because it can be changed into another prime (1722957351727) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 861478675860 + 861478675861.

It is an arithmetic number, because the mean of its divisors is an integer number (861478675861).

Almost surely, 2^{1722957351721} is an apocalyptic number.

It is an amenable number.

1722957351721 is a deficient number, since it is larger than the sum of its proper divisors (1).

1722957351721 is an equidigital number, since it uses as much as digits as its factorization.

1722957351721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1852200, while the sum is 52.

The spelling of 1722957351721 in words is "one trillion, seven hundred twenty-two billion, nine hundred fifty-seven million, three hundred fifty-one thousand, seven hundred twenty-one".