6404390 has 16 divisors (see below), whose sum is σ = 11718000. Its totient is φ = 2519520.

The previous prime is 6404381. The next prime is 6404401. The reversal of 6404390 is 934046.

It is a super-2 number, since 2×6404390² = 82032422544200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4640 + ... + 5859.

It is an arithmetic number, because the mean of its divisors is an integer number (732375).

Almost surely, 2^6404390 is an apocalyptic number.

6404390 is a deficient number, since it is larger than the sum of its proper divisors (5313610).

6404390 is a wasteful number, since it uses less digits than its factorization.

6404390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10567.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 6404390 is about 2530.6896293303. The cubic root of 6404390 is about 185.7059948398.

The spelling of 6404390 in words is "six million, four hundred four thousand, three hundred ninety".