641554560 has 256 divisors, whose sum is σ = 2297203200. Its totient is φ = 169205760.

The previous prime is 641554523. The next prime is 641554577. The reversal of 641554560 is 65455146.

641554560 is a `hidden beast` number, since 6 + 41 + 5 + 54 + 560 = 666.

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

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, 2367225 + ... + 2367495.

It is an arithmetic number, because the mean of its divisors is an integer number (8973450).

Almost surely, 2^641554560 is an apocalyptic number.

641554560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 641554560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1148601600).

641554560 is an abundant number, since it is smaller than the sum of its proper divisors (1655648640).

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

641554560 is a wasteful number, since it uses less digits than its factorization.

641554560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The square root of 641554560 is about 25328.9273361507. The cubic root of 641554560 is about 862.4710614109.

The spelling of 641554560 in words is "six hundred forty-one million, five hundred fifty-four thousand, five hundred sixty".