638441400 has 48 divisors (see below), whose sum is σ = 1979170200. Its totient is φ = 170250880.

The previous prime is 638441399. The next prime is 638441407. The reversal of 638441400 is 4144836.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638441407) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 531435 + ... + 532634.

Almost surely, 2^638441400 is an apocalyptic number.

638441400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638441400 is an abundant number, since it is smaller than the sum of its proper divisors (1340728800).

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

638441400 is a wasteful number, since it uses less digits than its factorization.

638441400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1064088 (or 1064079 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 638441400 is about 25267.3979665497. The cubic root of 638441400 is about 861.0737444610.

The spelling of 638441400 in words is "six hundred thirty-eight million, four hundred forty-one thousand, four hundred".