1721367617 has 2 divisors, whose sum is σ = 1721367618. Its totient is φ = 1721367616.

The previous prime is 1721367611. The next prime is 1721367631. The reversal of 1721367617 is 7167631271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1705359616 + 16008001 = 41296^2 + 4001^2 .

It is a cyclic number.

It is not a de Polignac number, because 1721367617 - 2⁶ = 1721367553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1721367611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860683808 + 860683809.

It is an arithmetic number, because the mean of its divisors is an integer number (860683809).

Almost surely, 2^1721367617 is an apocalyptic number.

It is an amenable number.

1721367617 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721367617 is an equidigital number, since it uses as much as digits as its factorization.

1721367617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 74088, while the sum is 41.

The square root of 1721367617 is about 41489.3675174737. The cubic root of 1721367617 is about 1198.4627577368.

Adding to 1721367617 its reverse (7167631271), we get a palindrome (8888998888).

The spelling of 1721367617 in words is "one billion, seven hundred twenty-one million, three hundred sixty-seven thousand, six hundred seventeen".