641643420 has 192 divisors, whose sum is σ = 2094833664. Its totient is φ = 145178880.

The previous prime is 641643413. The next prime is 641643437. The reversal of 641643420 is 24346146.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 652249 + ... + 653231.

It is an arithmetic number, because the mean of its divisors is an integer number (10910592).

Almost surely, 2^641643420 is an apocalyptic number.

641643420 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 641643420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1047416832).

641643420 is an abundant number, since it is smaller than the sum of its proper divisors (1453190244).

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

641643420 is a wasteful number, since it uses less digits than its factorization.

641643420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1072 (or 1070 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 641643420 is about 25330.6813962830. The cubic root of 641643420 is about 862.5108790898.

Adding to 641643420 its reverse (24346146), we get a palindrome (665989566).

The spelling of 641643420 in words is "six hundred forty-one million, six hundred forty-three thousand, four hundred twenty".