641028816 has 50 divisors (see below), whose sum is σ = 1855327122. Its totient is φ = 213675840.

The previous prime is 641028797. The next prime is 641028823. The reversal of 641028816 is 618820146.

641028816 is a `hidden beast` number, since 641 + 0 + 2 + 8 + 8 + 1 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 609892416 + 31136400 = 24696^2 + 5580^2 .

It is a super-3 number, since 3×641028816³ (a number of 27 digits) contains 333 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 246015 + ... + 248606.

Almost surely, 2^641028816 is an apocalyptic number.

It is an amenable number.

641028816 is an abundant number, since it is smaller than the sum of its proper divisors (1214298306).

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

641028816 is a wasteful number, since it uses less digits than its factorization.

641028816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494641 (or 494626 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 641028816 is about 25318.5468777337. The cubic root of 641028816 is about 862.2354031456.

The spelling of 641028816 in words is "six hundred forty-one million, twenty-eight thousand, eight hundred sixteen".