641249280 has 468 divisors, whose sum is σ = 2622037392. Its totient is φ = 144506880.

The previous prime is 641249261. The next prime is 641249281. The reversal of 641249280 is 82942146.

641249280 is a `hidden beast` number, since 641 + 2 + 4 + 9 + 2 + 8 + 0 = 666.

It is a super-2 number, since 2×641249280² = 822401278201036800, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (641249281) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 9031645 + ... + 9031715.

It is an arithmetic number, because the mean of its divisors is an integer number (5602644).

Almost surely, 2^641249280 is an apocalyptic number.

641249280 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 641249280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1311018696).

641249280 is an abundant number, since it is smaller than the sum of its proper divisors (1980788112).

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

641249280 is a wasteful number, since it uses less digits than its factorization.

641249280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 641249280 is about 25322.9003078241. The cubic root of 641249280 is about 862.3342390965.

The spelling of 641249280 in words is "six hundred forty-one million, two hundred forty-nine thousand, two hundred eighty".