1720644243 has 32 divisors (see below), whose sum is σ = 2402611200. Its totient is φ = 1094083200.

The previous prime is 1720644241. The next prime is 1720644287. The reversal of 1720644243 is 3424460271.

It is not a de Polignac number, because 1720644243 - 2¹ = 1720644241 is a prime.

It is a super-2 number, since 2×1720644243² = 5921233221938086098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1720644241) 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 in 31 ways as a sum of consecutive naturals, for example, 2726538 + ... + 2727168.

It is an arithmetic number, because the mean of its divisors is an integer number (75081600).

Almost surely, 2^1720644243 is an apocalyptic number.

1720644243 is a deficient number, since it is larger than the sum of its proper divisors (681966957).

1720644243 is a wasteful number, since it uses less digits than its factorization.

1720644243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1043.

The product of its (nonzero) digits is 32256, while the sum is 33.

The square root of 1720644243 is about 41480.6490185484. The cubic root of 1720644243 is about 1198.2948566918.

The spelling of 1720644243 in words is "one billion, seven hundred twenty million, six hundred forty-four thousand, two hundred forty-three".