1643136243 has 16 divisors (see below), whose sum is σ = 2510551296. Its totient is φ = 936413280.

The previous prime is 1643136239. The next prime is 1643136269. The reversal of 1643136243 is 3426313461.

It is not a de Polignac number, because 1643136243 - 2² = 1643136239 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1643136203) 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, 97053 + ... + 112718.

It is an arithmetic number, because the mean of its divisors is an integer number (156909456).

Almost surely, 2^1643136243 is an apocalyptic number.

1643136243 is a deficient number, since it is larger than the sum of its proper divisors (867415053).

1643136243 is a wasteful number, since it uses less digits than its factorization.

1643136243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210154.

The product of its digits is 31104, while the sum is 33.

The square root of 1643136243 is about 40535.6169682910. The cubic root of 1643136243 is about 1180.0249547054.

The spelling of 1643136243 in words is "one billion, six hundred forty-three million, one hundred thirty-six thousand, two hundred forty-three".