1721040017 has 2 divisors, whose sum is σ = 1721040018. Its totient is φ = 1721040016.

The previous prime is 1721040011. The next prime is 1721040019. The reversal of 1721040017 is 7100401271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1442784256 + 278255761 = 37984^2 + 16681^2 .

It is a cyclic number.

It is not a de Polignac number, because 1721040017 - 2⁶ = 1721039953 is a prime.

Together with 1721040019, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1721039974 and 1721040001.

It is not a weakly prime, because it can be changed into another prime (1721040011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860520008 + 860520009.

It is an arithmetic number, because the mean of its divisors is an integer number (860520009).

Almost surely, 2^1721040017 is an apocalyptic number.

It is an amenable number.

1721040017 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721040017 is an equidigital number, since it uses as much as digits as its factorization.

1721040017 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 1721040017 is about 41485.4193301695. The cubic root of 1721040017 is about 1198.3867249156.

Adding to 1721040017 its reverse (7100401271), we get a palindrome (8821441288).

The spelling of 1721040017 in words is "one billion, seven hundred twenty-one million, forty thousand, seventeen".