256404469 has 2 divisors, whose sum is σ = 256404470. Its totient is φ = 256404468.

The previous prime is 256404451. The next prime is 256404517. The reversal of 256404469 is 964404652.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155301444 + 101103025 = 12462^2 + 10055^2 .

It is a cyclic number.

It is not a de Polignac number, because 256404469 - 2⁹ = 256403957 is a prime.

It is a super-2 number, since 2×256404469² = 131486503446343922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (256404409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128202234 + 128202235.

It is an arithmetic number, because the mean of its divisors is an integer number (128202235).

Almost surely, 2^256404469 is an apocalyptic number.

It is an amenable number.

256404469 is a deficient number, since it is larger than the sum of its proper divisors (1).

256404469 is an equidigital number, since it uses as much as digits as its factorization.

256404469 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 207360, while the sum is 40.

The square root of 256404469 is about 16012.6346676617. The cubic root of 256404469 is about 635.2946482212.

The spelling of 256404469 in words is "two hundred fifty-six million, four hundred four thousand, four hundred sixty-nine".