6520401001 has 3 divisors (see below), whose sum is σ = 6520481751. Its totient is φ = 6520320252.

The previous prime is 6520400987. The next prime is 6520401059. The reversal of 6520401001 is 1001040256.

The square root of 6520401001 is 80749.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 6130733401 + 389667600 = 78299^2 + 19740^2 .

It is not a de Polignac number, because 6520401001 - 2⁵ = 6520400969 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6520401001.

It is not an unprimeable number, because it can be changed into a prime (6520401061) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 40375 + ... + 121123.

It is an arithmetic number, because the mean of its divisors is an integer number (2173493917).

Almost surely, 2^6520401001 is an apocalyptic number.

6520401001 is the 80749-th square number.

6520401001 is the 40375-th centered octagonal number.

It is an amenable number.

6520401001 is a deficient number, since it is larger than the sum of its proper divisors (80750).

6520401001 is an frugal number, since it uses more digits than its factorization.

6520401001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161498 (or 80749 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The cubic root of 6520401001 is about 1868.2060255141.

Adding to 6520401001 its reverse (1001040256), we get a palindrome (7521441257).

The spelling of 6520401001 in words is "six billion, five hundred twenty million, four hundred one thousand, one".