1643431343 has 4 divisors (see below), whose sum is σ = 1646350968. Its totient is φ = 1640511720.

The previous prime is 1643431337. The next prime is 1643431373. The reversal of 1643431343 is 3431343461.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1643431343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643431373) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1458968 + ... + 1460093.

It is an arithmetic number, because the mean of its divisors is an integer number (411587742).

Almost surely, 2^1643431343 is an apocalyptic number.

1643431343 is a deficient number, since it is larger than the sum of its proper divisors (2919625).

1643431343 is an equidigital number, since it uses as much as digits as its factorization.

1643431343 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2919624.

The product of its digits is 31104, while the sum is 32.

The square root of 1643431343 is about 40539.2568136122. The cubic root of 1643431343 is about 1180.0955928973.

The spelling of 1643431343 in words is "one billion, six hundred forty-three million, four hundred thirty-one thousand, three hundred forty-three".