638849700 has 288 divisors, whose sum is σ = 2187360000. Its totient is φ = 159667200.

The previous prime is 638849689. The next prime is 638849723. The reversal of 638849700 is 7948836.

It is a happy number.

638849700 is a `hidden beast` number, since 638 + 8 + 4 + 9 + 7 + 0 + 0 = 666.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3210201 + ... + 3210399.

It is an arithmetic number, because the mean of its divisors is an integer number (7595000).

Almost surely, 2^638849700 is an apocalyptic number.

638849700 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638849700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1093680000).

638849700 is an abundant number, since it is smaller than the sum of its proper divisors (1548510300).

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

638849700 is a wasteful number, since it uses less digits than its factorization.

638849700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 292 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 638849700 is about 25275.4762566405. The cubic root of 638849700 is about 861.2572650832.

The spelling of 638849700 in words is "six hundred thirty-eight million, eight hundred forty-nine thousand, seven hundred".