638913450 has 72 divisors (see below), whose sum is σ = 1843221312. Its totient is φ = 146035680.

The previous prime is 638913449. The next prime is 638913461. The reversal of 638913450 is 54319836.

It is a super-3 number, since 3×638913450³ (a number of 27 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 638913399 and 638913408.

It is an unprimeable number.

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 35 ways as a sum of consecutive naturals, for example, 36114 + ... + 50813.

It is an arithmetic number, because the mean of its divisors is an integer number (25600296).

Almost surely, 2^638913450 is an apocalyptic number.

638913450 is an abundant number, since it is smaller than the sum of its proper divisors (1204307862).

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

638913450 is a wasteful number, since it uses less digits than its factorization.

638913450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86956 (or 86944 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 638913450 is about 25276.7373290146. The cubic root of 638913450 is about 861.2859120532.

The spelling of 638913450 in words is "six hundred thirty-eight million, nine hundred thirteen thousand, four hundred fifty".