1720810901 has 2 divisors, whose sum is σ = 1720810902. Its totient is φ = 1720810900.

The previous prime is 1720810879. The next prime is 1720810913. The reversal of 1720810901 is 1090180271.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1147447876 + 573363025 = 33874^2 + 23945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1720810901 is a prime.

It is a super-2 number, since 2×1720810901² = 5922380314000863602, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1720810921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 860405450 + 860405451.

It is an arithmetic number, because the mean of its divisors is an integer number (860405451).

Almost surely, 2^1720810901 is an apocalyptic number.

It is an amenable number.

1720810901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1720810901 is an equidigital number, since it uses as much as digits as its factorization.

1720810901 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1008, while the sum is 29.

The square root of 1720810901 is about 41482.6578343288. The cubic root of 1720810901 is about 1198.3335435533. Note that the first 3 decimals are identical.

The spelling of 1720810901 in words is "one billion, seven hundred twenty million, eight hundred ten thousand, nine hundred one".