1720946321 has 2 divisors, whose sum is σ = 1720946322. Its totient is φ = 1720946320.

The previous prime is 1720946291. The next prime is 1720946399. The reversal of 1720946321 is 1236490271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 903844096 + 817102225 = 30064^2 + 28585^2 .

It is an emirp because it is prime and its reverse (1236490271) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1720946321 - 2²² = 1716752017 is a prime.

It is not a weakly prime, because it can be changed into another prime (1720946021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860473160 + 860473161.

It is an arithmetic number, because the mean of its divisors is an integer number (860473161).

Almost surely, 2^1720946321 is an apocalyptic number.

It is an amenable number.

1720946321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720946321 is an equidigital number, since it uses as much as digits as its factorization.

1720946321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 1720946321 is about 41484.2900505722. The cubic root of 1720946321 is about 1198.3649771973.

The spelling of 1720946321 in words is "one billion, seven hundred twenty million, nine hundred forty-six thousand, three hundred twenty-one".