1643139428 has 12 divisors (see below), whose sum is σ = 3286278912. Its totient is φ = 704202600.

The previous prime is 1643139427. The next prime is 1643139451. The reversal of 1643139428 is 8249313461.

1643139428 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (1643139427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29341748 + ... + 29341803.

It is an arithmetic number, because the mean of its divisors is an integer number (273856576).

Almost surely, 2^1643139428 is an apocalyptic number.

It is an amenable number.

1643139428 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1643139428 is a wasteful number, since it uses less digits than its factorization.

1643139428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58683562 (or 58683560 counting only the distinct ones).

The product of its digits is 124416, while the sum is 41.

The square root of 1643139428 is about 40535.6562547099. The cubic root of 1643139428 is about 1180.0257171452.

The spelling of 1643139428 in words is "one billion, six hundred forty-three million, one hundred thirty-nine thousand, four hundred twenty-eight".