641569838 has 32 divisors (see below), whose sum is σ = 1208625600. Its totient is φ = 253804320.

The previous prime is 641569781. The next prime is 641569909. The reversal of 641569838 is 838965146.

641569838 = 3487² + 3488² + ... + 3538².

641569838 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×641569838² = 823223714062692488, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 27053 + ... + 44888.

It is an arithmetic number, because the mean of its divisors is an integer number (37769550).

Almost surely, 2^641569838 is an apocalyptic number.

641569838 is a deficient number, since it is larger than the sum of its proper divisors (567055762).

641569838 is a wasteful number, since it uses less digits than its factorization.

641569838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71977 (or 71963 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 50.

The square root of 641569838 is about 25329.2289262820. The cubic root of 641569838 is about 862.4779076607.

The spelling of 641569838 in words is "six hundred forty-one million, five hundred sixty-nine thousand, eight hundred thirty-eight".