641632656 has 240 divisors, whose sum is σ = 2086473600. Its totient is φ = 168892416.

The previous prime is 641632601. The next prime is 641632687. The reversal of 641632656 is 656236146.

It is a super-2 number, since 2×641632656² = 823384930491228672, which contains 22 as substring.

Its product of digits (155520) is a multiple of the sum of its prime factors (486).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1568580 + ... + 1568988.

It is an arithmetic number, because the mean of its divisors is an integer number (8693640).

Almost surely, 2^641632656 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 641632656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1043236800).

641632656 is an abundant number, since it is smaller than the sum of its proper divisors (1444840944).

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

641632656 is a wasteful number, since it uses less digits than its factorization.

641632656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486 (or 473 counting only the distinct ones).

The product of its digits is 155520, while the sum is 39.

The square root of 641632656 is about 25330.4689257819. The cubic root of 641632656 is about 862.5060559961.

The spelling of 641632656 in words is "six hundred forty-one million, six hundred thirty-two thousand, six hundred fifty-six".