1645864828 has 12 divisors (see below), whose sum is σ = 2916723040. Its totient is φ = 812515392.

The previous prime is 1645864771. The next prime is 1645864837. The reversal of 1645864828 is 8284685461.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2603901 + ... + 2604532.

Almost surely, 2^1645864828 is an apocalyptic number.

It is an amenable number.

1645864828 is a deficient number, since it is larger than the sum of its proper divisors (1270858212).

1645864828 is a wasteful number, since it uses less digits than its factorization.

1645864828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5208516 (or 5208514 counting only the distinct ones).

The product of its digits is 2949120, while the sum is 52.

The square root of 1645864828 is about 40569.2596432323. The cubic root of 1645864828 is about 1180.6777749419.

The spelling of 1645864828 in words is "one billion, six hundred forty-five million, eight hundred sixty-four thousand, eight hundred twenty-eight".