1638593045 has 18 divisors (see below), whose sum is σ = 2017896354. Its totient is φ = 1277347680.

The previous prime is 1638593023. The next prime is 1638593053. The reversal of 1638593045 is 5403958361.

It can be written as a sum of positive squares in 3 ways, for example, as 242300356 + 1396292689 = 15566^2 + 37367^2 .

It is not a de Polignac number, because 1638593045 - 2¹² = 1638588949 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1638592987 and 1638593005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3891935 + ... + 3892355.

It is an arithmetic number, because the mean of its divisors is an integer number (112105353).

Almost surely, 2^1638593045 is an apocalyptic number.

It is an amenable number.

1638593045 is a deficient number, since it is larger than the sum of its proper divisors (379303309).

1638593045 is an frugal number, since it uses more digits than its factorization.

1638593045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933 (or 469 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 44.

The square root of 1638593045 is about 40479.5385966787. The cubic root of 1638593045 is about 1178.9363787792.

The spelling of 1638593045 in words is "one billion, six hundred thirty-eight million, five hundred ninety-three thousand, forty-five".