6520545021 has 8 divisors (see below), whose sum is σ = 8696660224. Its totient is φ = 4345729920.

The previous prime is 6520545019. The next prime is 6520545023. The reversal of 6520545021 is 1205450256.

It is an interprime number because it is at equal distance from previous prime (6520545019) and next prime (6520545023).

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

It is not a de Polignac number, because 6520545021 - 2¹ = 6520545019 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 6520545021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6520545023) 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, 313261 + ... + 333426.

It is an arithmetic number, because the mean of its divisors is an integer number (1087082528).

Almost surely, 2^6520545021 is an apocalyptic number.

It is an amenable number.

6520545021 is a deficient number, since it is larger than the sum of its proper divisors (2176115203).

6520545021 is a wasteful number, since it uses less digits than its factorization.

6520545021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650051.

The product of its (nonzero) digits is 12000, while the sum is 30.

The square root of 6520545021 is about 80749.8917708253. The cubic root of 6520545021 is about 1868.2197801411.

Adding to 6520545021 its reverse (1205450256), we get a palindrome (7725995277).

The spelling of 6520545021 in words is "six billion, five hundred twenty million, five hundred forty-five thousand, twenty-one".