641103821 has 8 divisors (see below), whose sum is σ = 644400504. Its totient is φ = 637816320.

The previous prime is 641103811. The next prime is 641103823. The reversal of 641103821 is 128301146.

It can be written as a sum of positive squares in 4 ways, for example, as 199515625 + 441588196 = 14125^2 + 21014^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641103821 is a prime.

It is a super-2 number, since 2×641103821² = 822028218601600082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641103823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168581 + ... + 172341.

It is an arithmetic number, because the mean of its divisors is an integer number (80550063).

Almost surely, 2^641103821 is an apocalyptic number.

It is an amenable number.

641103821 is a deficient number, since it is larger than the sum of its proper divisors (3296683).

641103821 is a wasteful number, since it uses less digits than its factorization.

641103821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4591.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 641103821 is about 25320.0280608059. The cubic root of 641103821 is about 862.2690310900.

Adding to 641103821 its reverse (128301146), we get a palindrome (769404967).

The spelling of 641103821 in words is "six hundred forty-one million, one hundred three thousand, eight hundred twenty-one".