6404551 has 2 divisors, whose sum is σ = 6404552. Its totient is φ = 6404550.

The previous prime is 6404527. The next prime is 6404581. The reversal of 6404551 is 1554046.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6404551 - 2¹⁷ = 6273479 is a prime.

It is an Ulam number.

6404551 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6404521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3202275 + 3202276.

It is an arithmetic number, because the mean of its divisors is an integer number (3202276).

Almost surely, 2^6404551 is an apocalyptic number.

6404551 is a deficient number, since it is larger than the sum of its proper divisors (1).

6404551 is an equidigital number, since it uses as much as digits as its factorization.

6404551 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 6404551 is about 2530.7214386416. The cubic root of 6404551 is about 185.7075509815.

Adding to 6404551 its reverse (1554046), we get a palindrome (7958597).

The spelling of 6404551 in words is "six million, four hundred four thousand, five hundred fifty-one".