6813505 has 4 divisors (see below), whose sum is σ = 8176212. Its totient is φ = 5450800.

The previous prime is 6813491. The next prime is 6813509. The reversal of 6813505 is 5053186.

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 5089536 + 1723969 = 2256^2 + 1313^2 .

It is not a de Polignac number, because 6813505 - 2⁵ = 6813473 is a prime.

It is a Duffinian number.

6813505 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6813509) 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, 681346 + ... + 681355.

It is an arithmetic number, because the mean of its divisors is an integer number (2044053).

Almost surely, 2^6813505 is an apocalyptic number.

It is an amenable number.

6813505 is a deficient number, since it is larger than the sum of its proper divisors (1362707).

6813505 is a wasteful number, since it uses less digits than its factorization.

6813505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1362706.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 6813505 is about 2610.2691432111. The cubic root of 6813505 is about 189.5789846713.

It can be divided in two parts, 681 and 3505, that added together give a triangular number (4186 = T₉₁).

The spelling of 6813505 in words is "six million, eight hundred thirteen thousand, five hundred five".