1643355131 has 4 divisors (see below), whose sum is σ = 1792751064. Its totient is φ = 1493959200.

The previous prime is 1643355127. The next prime is 1643355193. The reversal of 1643355131 is 1315533461.

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

It is a cyclic number.

It is not a de Polignac number, because 1643355131 - 2² = 1643355127 is a prime.

It is a super-2 number, since 2×1643355131² = 5401232173168054322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1643354131) 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, 74697950 + ... + 74697971.

It is an arithmetic number, because the mean of its divisors is an integer number (448187766).

Almost surely, 2^1643355131 is an apocalyptic number.

1643355131 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1643355131 is a deficient number, since it is larger than the sum of its proper divisors (149395933).

1643355131 is a wasteful number, since it uses less digits than its factorization.

1643355131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149395932.

The product of its digits is 16200, while the sum is 32.

The square root of 1643355131 is about 40538.3168249497. The cubic root of 1643355131 is about 1180.0773508137.

Adding to 1643355131 its reverse (1315533461), we get a palindrome (2958888592).

The spelling of 1643355131 in words is "one billion, six hundred forty-three million, three hundred fifty-five thousand, one hundred thirty-one".