1643161311 has 12 divisors (see below), whose sum is σ = 2589224040. Its totient is φ = 995855280.

The previous prime is 1643161301. The next prime is 1643161409. The reversal of 1643161311 is 1131613461.

1643161311 is a `hidden beast` number, since 1 + 6 + 4 + 31 + 613 + 11 = 666.

It is not a de Polignac number, because 1643161311 - 2⁷ = 1643161183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643161301) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8298696 + ... + 8298893.

It is an arithmetic number, because the mean of its divisors is an integer number (215768670).

Almost surely, 2^1643161311 is an apocalyptic number.

1643161311 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1643161311 is a deficient number, since it is larger than the sum of its proper divisors (946062729).

1643161311 is a wasteful number, since it uses less digits than its factorization.

1643161311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16597606 (or 16597603 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 1643161311 is about 40535.9261766646. The cubic root of 1643161311 is about 1180.0309555702.

Adding to 1643161311 its reverse (1131613461), we get a palindrome (2774774772).

The spelling of 1643161311 in words is "one billion, six hundred forty-three million, one hundred sixty-one thousand, three hundred eleven".