641440528 has 20 divisors (see below), whose sum is σ = 1244992860. Its totient is φ = 320152064.

The previous prime is 641440523. The next prime is 641440529. The reversal of 641440528 is 825044146.

It can be written as a sum of positive squares in 2 ways, for example, as 40602384 + 600838144 = 6372^2 + 24512^2 .

It is a super-2 number, since 2×641440528² = 822891901921837568, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 641440493 and 641440502.

It is not an unprimeable number, because it can be changed into a prime (641440523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26125 + ... + 44332.

It is an arithmetic number, because the mean of its divisors is an integer number (62249643).

Almost surely, 2^641440528 is an apocalyptic number.

It is an amenable number.

641440528 is a deficient number, since it is larger than the sum of its proper divisors (603552332).

641440528 is a wasteful number, since it uses less digits than its factorization.

641440528 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71034 (or 71028 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 34.

The square root of 641440528 is about 25326.6762130367. The cubic root of 641440528 is about 862.4199589099.

The spelling of 641440528 in words is "six hundred forty-one million, four hundred forty thousand, five hundred twenty-eight".