1643849400529 has 4 divisors (see below), whose sum is σ = 1878685029184. Its totient is φ = 1409013771876.

The previous prime is 1643849400439. The next prime is 1643849400533. The reversal of 1643849400529 is 9250049483461.

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 1643849400529 - 2²⁷ = 1643715182801 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1643849400529.

It is not an unprimeable number, because it can be changed into a prime (1643849400829) 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, 117417814317 + ... + 117417814330.

It is an arithmetic number, because the mean of its divisors is an integer number (469671257296).

Almost surely, 2^{1643849400529} is an apocalyptic number.

It is an amenable number.

1643849400529 is a deficient number, since it is larger than the sum of its proper divisors (234835628655).

1643849400529 is an equidigital number, since it uses as much as digits as its factorization.

1643849400529 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234835628654.

The product of its (nonzero) digits is 7464960, while the sum is 55.

The spelling of 1643849400529 in words is "one trillion, six hundred forty-three billion, eight hundred forty-nine million, four hundred thousand, five hundred twenty-nine".