1643456279873 has 16 divisors (see below), whose sum is σ = 1656730743936. Its totient is φ = 1630215417600.

The previous prime is 1643456279863. The next prime is 1643456279891. The reversal of 1643456279873 is 3789726543461.

It is a cyclic number.

It is not a de Polignac number, because 1643456279873 - 2¹⁴ = 1643456263489 is a prime.

It is a super-2 number, since 2×1643456279873² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643456279813) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 444535961 + ... + 444539657.

It is an arithmetic number, because the mean of its divisors is an integer number (103545671496).

Almost surely, 2^{1643456279873} is an apocalyptic number.

It is an amenable number.

1643456279873 is a deficient number, since it is larger than the sum of its proper divisors (13274464063).

1643456279873 is a wasteful number, since it uses less digits than its factorization.

1643456279873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7304.

The product of its digits is 182891520, while the sum is 65.

The spelling of 1643456279873 in words is "one trillion, six hundred forty-three billion, four hundred fifty-six million, two hundred seventy-nine thousand, eight hundred seventy-three".