6405945 has 72 divisors (see below), whose sum is σ = 13386816. Its totient is φ = 2560896.

The previous prime is 6405943. The next prime is 6405979. The reversal of 6405945 is 5495046.

It is not a de Polignac number, because 6405945 - 2¹ = 6405943 is a prime.

It is a super-2 number, since 2×6405945² = 82072262686050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6405941) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 337146 + ... + 337164.

It is an arithmetic number, because the mean of its divisors is an integer number (185928).

Almost surely, 2^6405945 is an apocalyptic number.

6405945 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

6405945 is an abundant number, since it is smaller than the sum of its proper divisors (6980871).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6405945 is a wasteful number, since it uses less digits than its factorization.

6405945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 6405945 is about 2530.9968391920. The cubic root of 6405945 is about 185.7210235651.

The spelling of 6405945 in words is "six million, four hundred five thousand, nine hundred forty-five".