641205828 has 48 divisors (see below), whose sum is σ = 1685819520. Its totient is φ = 210722400.

The previous prime is 641205827. The next prime is 641205883. The reversal of 641205828 is 828502146.

641205828 is a `hidden beast` number, since 64 + 12 + 0 + 582 + 8 = 666.

It is a super-2 number, since 2×641205828² = 822289827722331168, 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 = 641205792 and 641205801.

It is not an unprimeable number, because it can be changed into a prime (641205821) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34143 + ... + 49478.

It is an arithmetic number, because the mean of its divisors is an integer number (35121240).

Almost surely, 2^641205828 is an apocalyptic number.

It is an amenable number.

641205828 is an abundant number, since it is smaller than the sum of its proper divisors (1044613692).

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

641205828 is a wasteful number, since it uses less digits than its factorization.

641205828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83705 (or 83697 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 641205828 is about 25322.0423346933. The cubic root of 641205828 is about 862.3147609752.

The spelling of 641205828 in words is "six hundred forty-one million, two hundred five thousand, eight hundred twenty-eight".