1638630144 has 108 divisors (see below), whose sum is σ = 4743261432. Its totient is φ = 544051200.

The previous prime is 1638630143. The next prime is 1638630163. The reversal of 1638630144 is 4410368361.

It is a happy number.

1638630144 is a `hidden beast` number, since 1 + 6 + 3 + 8 + 630 + 14 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1638630099 and 1638630108.

It is not an unprimeable number, because it can be changed into a prime (1638630143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 646159 + ... + 648689.

Almost surely, 2^1638630144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638630144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2371630716).

1638630144 is an abundant number, since it is smaller than the sum of its proper divisors (3104631288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1638630144 is a wasteful number, since it uses less digits than its factorization.

1638630144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2834 (or 2817 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 1638630144 is about 40479.9968379445. The cubic root of 1638630144 is about 1178.9452760525.

The spelling of 1638630144 in words is "one billion, six hundred thirty-eight million, six hundred thirty thousand, one hundred forty-four".