1638878068 has 24 divisors (see below), whose sum is σ = 2908039680. Its totient is φ = 808036320.

The previous prime is 1638878063. The next prime is 1638878069. The reversal of 1638878068 is 8608788361.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1638878063) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 285030 + ... + 290722.

It is an arithmetic number, because the mean of its divisors is an integer number (121168320).

Almost surely, 2^1638878068 is an apocalyptic number.

It is an amenable number.

1638878068 is a deficient number, since it is larger than the sum of its proper divisors (1269161612).

1638878068 is a wasteful number, since it uses less digits than its factorization.

1638878068 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6687 (or 6685 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 55.

The square root of 1638878068 is about 40483.0590247328. The cubic root of 1638878068 is about 1179.0047310165.

The spelling of 1638878068 in words is "one billion, six hundred thirty-eight million, eight hundred seventy-eight thousand, sixty-eight".