1721611673 has 2 divisors, whose sum is σ = 1721611674. Its totient is φ = 1721611672.

The previous prime is 1721611649. The next prime is 1721611721. The reversal of 1721611673 is 3761161271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1680754009 + 40857664 = 40997^2 + 6392^2 .

It is a cyclic number.

It is not a de Polignac number, because 1721611673 - 2⁸ = 1721611417 is a prime.

It is not a weakly prime, because it can be changed into another prime (1721611643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860805836 + 860805837.

It is an arithmetic number, because the mean of its divisors is an integer number (860805837).

Almost surely, 2^1721611673 is an apocalyptic number.

It is an amenable number.

1721611673 is a deficient number, since it is larger than the sum of its proper divisors (1).

1721611673 is an equidigital number, since it uses as much as digits as its factorization.

1721611673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10584, while the sum is 35.

The square root of 1721611673 is about 41492.3086005105. The cubic root of 1721611673 is about 1198.5193945260.

The spelling of 1721611673 in words is "one billion, seven hundred twenty-one million, six hundred eleven thousand, six hundred seventy-three".