6404381 has 2 divisors, whose sum is σ = 6404382. Its totient is φ = 6404380.

The previous prime is 6404369. The next prime is 6404401. The reversal of 6404381 is 1834046.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6400900 + 3481 = 2530^2 + 59^2 .

It is a cyclic number.

It is not a de Polignac number, because 6404381 - 2⁶ = 6404317 is a prime.

It is a super-2 number, since 2×6404381² = 82032191986322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6404381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6404341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3202190 + 3202191.

It is an arithmetic number, because the mean of its divisors is an integer number (3202191).

Almost surely, 2^6404381 is an apocalyptic number.

It is an amenable number.

6404381 is a deficient number, since it is larger than the sum of its proper divisors (1).

6404381 is an equidigital number, since it uses as much as digits as its factorization.

6404381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 6404381 is about 2530.6878511583. The cubic root of 6404381 is about 185.7059078497.

The spelling of 6404381 in words is "six million, four hundred four thousand, three hundred eighty-one".