1638504450 has 120 divisors (see below), whose sum is σ = 4966624080. Its totient is φ = 397202400.

The previous prime is 1638504419. The next prime is 1638504457. The reversal of 1638504450 is 544058361.

It is a happy number.

1638504450 is a `hidden beast` number, since 163 + 8 + 50 + 445 + 0 = 666.

It is not an unprimeable number, because it can be changed into a prime (1638504457) 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 59 ways as a sum of consecutive naturals, for example, 26161 + ... + 62939.

It is an arithmetic number, because the mean of its divisors is an integer number (41388534).

Almost surely, 2^1638504450 is an apocalyptic number.

1638504450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1638504450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2483312040).

1638504450 is an abundant number, since it is smaller than the sum of its proper divisors (3328119630).

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

1638504450 is a wasteful number, since it uses less digits than its factorization.

1638504450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36814 (or 36800 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 1638504450 is about 40478.4442635831. Note that the first 3 decimals coincide. The cubic root of 1638504450 is about 1178.9151309265.

The spelling of 1638504450 in words is "one billion, six hundred thirty-eight million, five hundred four thousand, four hundred fifty".