1638574856 has 16 divisors (see below), whose sum is σ = 3143778000. Its totient is φ = 800234064.

The previous prime is 1638574853. The next prime is 1638574867. The reversal of 1638574856 is 6584758361.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 1638574798 and 1638574807.

It is not an unprimeable number, because it can be changed into a prime (1638574853) 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, 2381306 + ... + 2381993.

It is an arithmetic number, because the mean of its divisors is an integer number (196486125).

Almost surely, 2^1638574856 is an apocalyptic number.

It is an amenable number.

1638574856 is a deficient number, since it is larger than the sum of its proper divisors (1505203144).

1638574856 is a wasteful number, since it uses less digits than its factorization.

1638574856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4763348 (or 4763344 counting only the distinct ones).

The product of its digits is 4838400, while the sum is 53.

The square root of 1638574856 is about 40479.3139269924. The cubic root of 1638574856 is about 1178.9320165504.

The spelling of 1638574856 in words is "one billion, six hundred thirty-eight million, five hundred seventy-four thousand, eight hundred fifty-six".