6405555 has 32 divisors (see below), whose sum is σ = 11176704. Its totient is φ = 3113856.

The previous prime is 6405547. The next prime is 6405559. The reversal of 6405555 is 5555046.

It is not a de Polignac number, because 6405555 - 2³ = 6405547 is a prime.

It is a super-2 number, since 2×6405555² = 82062269716050, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

6405555 is a modest number, since divided by 5555 gives 640 as remainder.

It is not an unprimeable number, because it can be changed into a prime (6405559) 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, 20712 + ... + 21018.

It is an arithmetic number, because the mean of its divisors is an integer number (349272).

Almost surely, 2^6405555 is an apocalyptic number.

6405555 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

6405555 is a deficient number, since it is larger than the sum of its proper divisors (4771149).

6405555 is a wasteful number, since it uses less digits than its factorization.

6405555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435.

The product of its (nonzero) digits is 15000, while the sum is 30.

The square root of 6405555 is about 2530.9197932767. The cubic root of 6405555 is about 185.7172545313.

The spelling of 6405555 in words is "six million, four hundred five thousand, five hundred fifty-five".