1638973816 has 32 divisors (see below), whose sum is σ = 3116088000. Its totient is φ = 808045056.

The previous prime is 1638973771. The next prime is 1638973837. The reversal of 1638973816 is 6183798361.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 712380 + ... + 714676.

It is an arithmetic number, because the mean of its divisors is an integer number (97377750).

Almost surely, 2^1638973816 is an apocalyptic number.

It is an amenable number.

1638973816 is a deficient number, since it is larger than the sum of its proper divisors (1477114184).

1638973816 is a wasteful number, since it uses less digits than its factorization.

1638973816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3511 (or 3507 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 52.

The square root of 1638973816 is about 40484.2415761985. The cubic root of 1638973816 is about 1179.0276908590.

The spelling of 1638973816 in words is "one billion, six hundred thirty-eight million, nine hundred seventy-three thousand, eight hundred sixteen".