1643042938673 has 4 divisors (see below), whose sum is σ = 1658994811968. Its totient is φ = 1627091065380.

The previous prime is 1643042938637. The next prime is 1643042938729. The reversal of 1643042938673 is 3768392403461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1643042938673 - 2²⁰ = 1643041890097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643042938373) 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, 7975936493 + ... + 7975936698.

It is an arithmetic number, because the mean of its divisors is an integer number (414748702992).

Almost surely, 2^{1643042938673} is an apocalyptic number.

It is an amenable number.

1643042938673 is a deficient number, since it is larger than the sum of its proper divisors (15951873295).

1643042938673 is a wasteful number, since it uses less digits than its factorization.

1643042938673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15951873294.

The product of its (nonzero) digits is 15676416, while the sum is 56.

The spelling of 1643042938673 in words is "one trillion, six hundred forty-three billion, forty-two million, nine hundred thirty-eight thousand, six hundred seventy-three".