6540223513 has 4 divisors (see below), whose sum is σ = 6540537780. Its totient is φ = 6539909248.

The previous prime is 6540223511. The next prime is 6540223523. The reversal of 6540223513 is 3153220456.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1947721689 + 4592501824 = 44133^2 + 67768^2 .

It is a cyclic number.

It is not a de Polignac number, because 6540223513 - 2¹ = 6540223511 is a prime.

It is a super-2 number, since 2×6540223513² = 85549047199996122338, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6540223511) 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, 123520 + ... + 168337.

It is an arithmetic number, because the mean of its divisors is an integer number (1635134445).

Almost surely, 2^6540223513 is an apocalyptic number.

It is an amenable number.

6540223513 is a deficient number, since it is larger than the sum of its proper divisors (314267).

6540223513 is a wasteful number, since it uses less digits than its factorization.

6540223513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 314266.

The product of its (nonzero) digits is 21600, while the sum is 31.

The square root of 6540223513 is about 80871.6483880476. The cubic root of 6540223513 is about 1870.0972728147.

Adding to 6540223513 its reverse (3153220456), we get a palindrome (9693443969).

The spelling of 6540223513 in words is "six billion, five hundred forty million, two hundred twenty-three thousand, five hundred thirteen".