1643163861025 has 24 divisors (see below), whose sum is σ = 2145610216800. Its totient is φ = 1244852294400.

The previous prime is 1643163860993. The next prime is 1643163861029. The reversal of 1643163861025 is 5201683613461.

It is not a de Polignac number, because 1643163861025 - 2⁵ = 1643163860993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1643163861029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 518841 + ... + 1885609.

It is an arithmetic number, because the mean of its divisors is an integer number (89400425700).

Almost surely, 2^{1643163861025} is an apocalyptic number.

It is an amenable number.

1643163861025 is a deficient number, since it is larger than the sum of its proper divisors (502446355775).

1643163861025 is a wasteful number, since it uses less digits than its factorization.

1643163861025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1369329 (or 1369324 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The spelling of 1643163861025 in words is "one trillion, six hundred forty-three billion, one hundred sixty-three million, eight hundred sixty-one thousand, twenty-five".