641011656 has 128 divisors (see below), whose sum is σ = 1794078720. Its totient is φ = 189809664.

The previous prime is 641011603. The next prime is 641011661. The reversal of 641011656 is 656110146.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 778461 + ... + 779283.

It is an arithmetic number, because the mean of its divisors is an integer number (14016240).

Almost surely, 2^641011656 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 641011656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (897039360).

641011656 is an abundant number, since it is smaller than the sum of its proper divisors (1153067064).

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

641011656 is a wasteful number, since it uses less digits than its factorization.

641011656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 955 (or 951 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 641011656 is about 25318.2079934580. The cubic root of 641011656 is about 862.2277092161.

The spelling of 641011656 in words is "six hundred forty-one million, eleven thousand, six hundred fifty-six".