641269440 has 448 divisors, whose sum is σ = 2703697920. Its totient is φ = 139898880.

The previous prime is 641269439. The next prime is 641269471. The reversal of 641269440 is 44962146.

641269440 is a `hidden beast` number, since 641 + 2 + 6 + 9 + 4 + 4 + 0 = 666.

641269440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (448).

It is a super-2 number, since 2×641269440² = 822452989355827200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 641269395 and 641269404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1390810 + ... + 1391270.

It is an arithmetic number, because the mean of its divisors is an integer number (6035040).

Almost surely, 2^641269440 is an apocalyptic number.

641269440 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 641269440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1351848960).

641269440 is an abundant number, since it is smaller than the sum of its proper divisors (2062428480).

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

641269440 is a wasteful number, since it uses less digits than its factorization.

641269440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 517 (or 501 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 641269440 is about 25323.2983633649. The cubic root of 641269440 is about 862.3432758713.

The spelling of 641269440 in words is "six hundred forty-one million, two hundred sixty-nine thousand, four hundred forty".