1643243534 has 4 divisors (see below), whose sum is σ = 2464865304. Its totient is φ = 821621766.

The previous prime is 1643243531. The next prime is 1643243543. The reversal of 1643243534 is 4353423461.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 1643243494 and 1643243503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643243531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410810882 + ... + 410810885.

It is an arithmetic number, because the mean of its divisors is an integer number (616216326).

Almost surely, 2^1643243534 is an apocalyptic number.

1643243534 is a deficient number, since it is larger than the sum of its proper divisors (821621770).

1643243534 is an equidigital number, since it uses as much as digits as its factorization.

1643243534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 821621769.

The product of its digits is 103680, while the sum is 35.

The square root of 1643243534 is about 40536.9403630812. The cubic root of 1643243534 is about 1180.0506379686.

Adding to 1643243534 its reverse (4353423461), we get a palindrome (5996666995).

The spelling of 1643243534 in words is "one billion, six hundred forty-three million, two hundred forty-three thousand, five hundred thirty-four".