6403581 has 6 divisors (see below), whose sum is σ = 9249630. Its totient is φ = 4269048.

The previous prime is 6403571. The next prime is 6403601. The reversal of 6403581 is 1853046.

It can be written as a sum of positive squares in only one way, i.e., 4347225 + 2056356 = 2085^2 + 1434^2 .

It is not a de Polignac number, because 6403581 - 2¹¹ = 6401533 is a prime.

It is a super-2 number, since 2×6403581² = 82011699247122, which contains 22 as substring.

6403581 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6403511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 355746 + ... + 355763.

It is an arithmetic number, because the mean of its divisors is an integer number (1541605).

Almost surely, 2^6403581 is an apocalyptic number.

It is an amenable number.

6403581 is a deficient number, since it is larger than the sum of its proper divisors (2846049).

6403581 is a wasteful number, since it uses less digits than its factorization.

6403581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 711515 (or 711512 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 6403581 is about 2530.5297864281. The cubic root of 6403581 is about 185.6981750747.

The spelling of 6403581 in words is "six million, four hundred three thousand, five hundred eighty-one".