1643584138 has 16 divisors (see below), whose sum is σ = 2886295104. Its totient is φ = 687212640.

The previous prime is 1643584127. The next prime is 1643584147. The reversal of 1643584138 is 8314853461.

It is a junction number, because it is equal to n+sod(n) for n = 1643584094 and 1643584103.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1431120 + ... + 1432267.

It is an arithmetic number, because the mean of its divisors is an integer number (180393444).

Almost surely, 2^1643584138 is an apocalyptic number.

1643584138 is a deficient number, since it is larger than the sum of its proper divisors (1242710966).

1643584138 is a wasteful number, since it uses less digits than its factorization.

1643584138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2863437.

The product of its digits is 276480, while the sum is 43.

The square root of 1643584138 is about 40541.1413011523. The cubic root of 1643584138 is about 1180.1321641682.

The spelling of 1643584138 in words is "one billion, six hundred forty-three million, five hundred eighty-four thousand, one hundred thirty-eight".