6813945 has 24 divisors (see below), whose sum is σ = 12037896. Its totient is φ = 3564288.

The previous prime is 6813943. The next prime is 6813949. The reversal of 6813945 is 5493186.

It can be written as a sum of positive squares in 4 ways, for example, as 1710864 + 5103081 = 1308^2 + 2259^2 .

It is not a de Polignac number, because 6813945 - 2¹ = 6813943 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6813943) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 957 + ... + 3813.

It is an arithmetic number, because the mean of its divisors is an integer number (501579).

Almost surely, 2^6813945 is an apocalyptic number.

It is an amenable number.

6813945 is a deficient number, since it is larger than the sum of its proper divisors (5223951).

6813945 is a wasteful number, since it uses less digits than its factorization.

6813945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2921 (or 2918 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 6813945 is about 2610.3534243470. The cubic root of 6813945 is about 189.5830654372.

The spelling of 6813945 in words is "six million, eight hundred thirteen thousand, nine hundred forty-five".