1643575349 has 4 divisors (see below), whose sum is σ = 1770004236. Its totient is φ = 1517146464.

The previous prime is 1643575327. The next prime is 1643575361. The reversal of 1643575349 is 9435753461.

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

It can be written as a sum of positive squares in 2 ways, for example, as 368371249 + 1275204100 = 19193^2 + 35710^2 .

It is a cyclic number.

It is not a de Polignac number, because 1643575349 - 2²⁴ = 1626798133 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643575309) 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, 63214424 + ... + 63214449.

It is an arithmetic number, because the mean of its divisors is an integer number (442501059).

Almost surely, 2^1643575349 is an apocalyptic number.

It is an amenable number.

1643575349 is a deficient number, since it is larger than the sum of its proper divisors (126428887).

1643575349 is a wasteful number, since it uses less digits than its factorization.

1643575349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126428886.

The product of its digits is 1360800, while the sum is 47.

The square root of 1643575349 is about 40541.0329049471. The cubic root of 1643575349 is about 1180.1300605947.

The spelling of 1643575349 in words is "one billion, six hundred forty-three million, five hundred seventy-five thousand, three hundred forty-nine".