646511064 has 64 divisors (see below), whose sum is σ = 1664582400. Its totient is φ = 209096064.

The previous prime is 646511057. The next prime is 646511077. The reversal of 646511064 is 460115646.

It is a happy number.

646511064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 413917 + ... + 415475.

It is an arithmetic number, because the mean of its divisors is an integer number (26009100).

Almost surely, 2^646511064 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646511064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (832291200).

646511064 is an abundant number, since it is smaller than the sum of its proper divisors (1018071336).

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

646511064 is a wasteful number, since it uses less digits than its factorization.

646511064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2072 (or 2068 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 33.

The square root of 646511064 is about 25426.5818386979. The cubic root of 646511064 is about 864.6864507816.

The spelling of 646511064 in words is "six hundred forty-six million, five hundred eleven thousand, sixty-four".