648638172 has 192 divisors, whose sum is σ = 2137497600. Its totient is φ = 165473280.

The previous prime is 648638171. The next prime is 648638233. The reversal of 648638172 is 271836846.

648638172 is a `hidden beast` number, since 6 + 4 + 8 + 638 + 1 + 7 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648638171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 303604 + ... + 305732.

It is an arithmetic number, because the mean of its divisors is an integer number (11132800).

Almost surely, 2^648638172 is an apocalyptic number.

648638172 is a gapful number since it is divisible by the number (62) 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 648638172, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1068748800).

648638172 is an abundant number, since it is smaller than the sum of its proper divisors (1488859428).

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

648638172 is a wasteful number, since it uses less digits than its factorization.

648638172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2193 (or 2185 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 648638172 is about 25468.3759199522. The cubic root of 648638172 is about 865.6337240703.

The spelling of 648638172 in words is "six hundred forty-eight million, six hundred thirty-eight thousand, one hundred seventy-two".