638291016 has 192 divisors, whose sum is σ = 2059948800. Its totient is φ = 183124800.

The previous prime is 638290987. The next prime is 638291047. The reversal of 638291016 is 610192836.

638291016 is a `hidden beast` number, since 638 + 2 + 9 + 1 + 0 + 16 = 666.

It is a super-2 number, since 2×638291016² = 814830842212624512, which contains 22 as substring.

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

It is a zygodrome in base 3.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 405511 + ... + 407081.

It is an arithmetic number, because the mean of its divisors is an integer number (10728900).

Almost surely, 2^638291016 is an apocalyptic number.

638291016 is a gapful number since it is divisible by the number (66) 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 638291016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1029974400).

638291016 is an abundant number, since it is smaller than the sum of its proper divisors (1421657784).

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

638291016 is a wasteful number, since it uses less digits than its factorization.

638291016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1622 (or 1606 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 638291016 is about 25264.4219407451. The cubic root of 638291016 is about 861.0061309037.

The spelling of 638291016 in words is "six hundred thirty-eight million, two hundred ninety-one thousand, sixteen".