1720380401 has 2 divisors, whose sum is σ = 1720380402. Its totient is φ = 1720380400.

The previous prime is 1720380397. The next prime is 1720380419. The reversal of 1720380401 is 1040830271.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1263447025 + 456933376 = 35545^2 + 21376^2 .

It is a cyclic number.

It is not a de Polignac number, because 1720380401 - 2² = 1720380397 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1720380451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860190200 + 860190201.

It is an arithmetic number, because the mean of its divisors is an integer number (860190201).

Almost surely, 2^1720380401 is an apocalyptic number.

It is an amenable number.

1720380401 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720380401 is an equidigital number, since it uses as much as digits as its factorization.

1720380401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 1720380401 is about 41477.4685944068. The cubic root of 1720380401 is about 1198.2336050851.

The spelling of 1720380401 in words is "one billion, seven hundred twenty million, three hundred eighty thousand, four hundred one".