641920 has 64 divisors (see below), whose sum is σ = 1652400. Its totient is φ = 237568.

The previous prime is 641909. The next prime is 641923. The reversal of 641920 is 29146.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×641920² = 824122572800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641891 and 641900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641923) by changing a digit.

641920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10851 + ... + 10909.

2⁶⁴¹⁹²⁰ 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 641920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (826200).

641920 is an abundant number, since it is smaller than the sum of its proper divisors (1010480).

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

641920 is a wasteful number, since it uses less digits than its factorization.

641920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 83 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 641920 is about 801.1991013475. The cubic root of 641920 is about 86.2634789548.

The spelling of 641920 in words is "six hundred forty-one thousand, nine hundred twenty".