641726680 has 128 divisors (see below), whose sum is σ = 1733114880. Its totient is φ = 209088000.

The previous prime is 641726677. The next prime is 641726681. The reversal of 641726680 is 86627146.

641726680 = T₃₈₄ + T₃₈₅ + ... + T₁₅₇₄.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641726681) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1616242 + ... + 1616638.

It is an arithmetic number, because the mean of its divisors is an integer number (13539960).

Almost surely, 2^641726680 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 641726680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (866557440).

641726680 is an abundant number, since it is smaller than the sum of its proper divisors (1091388200).

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

641726680 is a wasteful number, since it uses less digits than its factorization.

641726680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 685 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 641726680 is about 25332.3248044865. The cubic root of 641726680 is about 862.5481841036.

The spelling of 641726680 in words is "six hundred forty-one million, seven hundred twenty-six thousand, six hundred eighty".