1643223231 has 24 divisors (see below), whose sum is σ = 2638586496. Its totient is φ = 978592320.

The previous prime is 1643223221. The next prime is 1643223251. The reversal of 1643223231 is 1323223461.

1643223231 is a `hidden beast` number, since 16 + 4 + 322 + 323 + 1 = 666.

It is not a de Polignac number, because 1643223231 - 2¹¹ = 1643221183 is a prime.

It is a super-2 number, since 2×1643223231² = 5400365173796158722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1643223195 and 1643223204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1643223221) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 222900 + ... + 230153.

It is an arithmetic number, because the mean of its divisors is an integer number (109941104).

Almost surely, 2^1643223231 is an apocalyptic number.

1643223231 is a deficient number, since it is larger than the sum of its proper divisors (995363265).

1643223231 is a wasteful number, since it uses less digits than its factorization.

1643223231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453103 (or 453100 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The square root of 1643223231 is about 40536.6899364021. The cubic root of 1643223231 is about 1180.0457779329.

Adding to 1643223231 its reverse (1323223461), we get a palindrome (2966446692).

The spelling of 1643223231 in words is "one billion, six hundred forty-three million, two hundred twenty-three thousand, two hundred thirty-one".