1721417 has 2 divisors, whose sum is σ = 1721418. Its totient is φ = 1721416.

The previous prime is 1721407. The next prime is 1721441. The reversal of 1721417 is 7141271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1042441 + 678976 = 1021^2 + 824^2 .

It is a cyclic number.

It is not a de Polignac number, because 1721417 - 2¹² = 1717321 is a prime.

It is a nialpdrome in base 8.

It is a junction number, because it is equal to n+sod(n) for n = 1721392 and 1721401.

It is not a weakly prime, because it can be changed into another prime (1721407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860708 + 860709.

It is an arithmetic number, because the mean of its divisors is an integer number (860709).

2^1721417 is an apocalyptic number.

It is an amenable number.

1721417 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721417 is an equidigital number, since it uses as much as digits as its factorization.

1721417 is an evil number, because the sum of its binary digits is even.

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

The square root of 1721417 is about 1312.0278198270. The cubic root of 1721417 is about 119.8474218221.

Adding to 1721417 its sum of digits (23), we get a triangular number (1721440 = T₁₈₅₅).

Adding to 1721417 its reverse (7141271), we get a palindrome (8862688).

The spelling of 1721417 in words is "one million, seven hundred twenty-one thousand, four hundred seventeen".