1643741723 has 16 divisors (see below), whose sum is σ = 1781435040. Its totient is φ = 1507693824.

The previous prime is 1643741719. The next prime is 1643741741. The reversal of 1643741723 is 3271473461.

It is a happy number.

It is not a de Polignac number, because 1643741723 - 2² = 1643741719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643141723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2493968 + ... + 2494626.

It is an arithmetic number, because the mean of its divisors is an integer number (111339690).

Almost surely, 2^1643741723 is an apocalyptic number.

1643741723 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1643741723 is a deficient number, since it is larger than the sum of its proper divisors (137693317).

1643741723 is a wasteful number, since it uses less digits than its factorization.

1643741723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1598.

The product of its digits is 84672, while the sum is 38.

The square root of 1643741723 is about 40543.0847741017. The cubic root of 1643741723 is about 1180.1698795447.

The spelling of 1643741723 in words is "one billion, six hundred forty-three million, seven hundred forty-one thousand, seven hundred twenty-three".