6521345645 has 32 divisors (see below), whose sum is σ = 8227173888. Its totient is φ = 4956553728.

The previous prime is 6521345591. The next prime is 6521345647. The reversal of 6521345645 is 5465431256.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 6521345645 - 2¹² = 6521341549 is a prime.

It is a super-3 number, since 3×6521345645³ (a number of 30 digits) contains 333 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 (6521345647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6842489 + ... + 6843441.

It is an arithmetic number, because the mean of its divisors is an integer number (257099184).

Almost surely, 2^6521345645 is an apocalyptic number.

It is an amenable number.

6521345645 is a deficient number, since it is larger than the sum of its proper divisors (1705828243).

6521345645 is a wasteful number, since it uses less digits than its factorization.

6521345645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1829.

The product of its digits is 432000, while the sum is 41.

The square root of 6521345645 is about 80754.8490494534. The cubic root of 6521345645 is about 1868.2962400268.

The spelling of 6521345645 in words is "six billion, five hundred twenty-one million, three hundred forty-five thousand, six hundred forty-five".