646331400 has 672 divisors, whose sum is σ = 2732325120. Its totient is φ = 139968000.

The previous prime is 646331377. The next prime is 646331461. The reversal of 646331400 is 4133646.

646331400 is a `hidden beast` number, since 646 + 3 + 3 + 14 + 0 + 0 = 666.

It is a super-3 number, since 3×646331400³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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 167 ways as a sum of consecutive naturals, for example, 20849385 + ... + 20849415.

It is an arithmetic number, because the mean of its divisors is an integer number (4065960).

Almost surely, 2^646331400 is an apocalyptic number.

646331400 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 646331400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1366162560).

646331400 is an abundant number, since it is smaller than the sum of its proper divisors (2085993720).

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

646331400 is a wasteful number, since it uses less digits than its factorization.

646331400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 65 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 646331400 is about 25423.0485976800. The cubic root of 646331400 is about 864.6063452077.

The spelling of 646331400 in words is "six hundred forty-six million, three hundred thirty-one thousand, four hundred".