641726064 has 480 divisors, whose sum is σ = 2404846080. Its totient is φ = 161243136.

The previous prime is 641726053. The next prime is 641726077. The reversal of 641726064 is 460627146.

641726064 is a `hidden beast` number, since 6 + 41 + 7 + 2 + 606 + 4 = 666.

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

It is a congruent number.

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, 8790732 + ... + 8790804.

It is an arithmetic number, because the mean of its divisors is an integer number (5010096).

Almost surely, 2^641726064 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 641726064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1202423040).

641726064 is an abundant number, since it is smaller than the sum of its proper divisors (1763120016).

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

641726064 is a wasteful number, since it uses less digits than its factorization.

641726064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 121 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 36.

The square root of 641726064 is about 25332.3126461048. The cubic root of 641726064 is about 862.5479081139.

The spelling of 641726064 in words is "six hundred forty-one million, seven hundred twenty-six thousand, sixty-four".