256402489 has 8 divisors (see below), whose sum is σ = 300951488. Its totient is φ = 213833520.

The previous prime is 256402481. The next prime is 256402529. The reversal of 256402489 is 984204652.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 256402489 - 2³ = 256402481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256402481) 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 in 7 ways as a sum of consecutive naturals, for example, 494727 + ... + 495244.

It is an arithmetic number, because the mean of its divisors is an integer number (37618936).

Almost surely, 2^256402489 is an apocalyptic number.

It is an amenable number.

256402489 is a deficient number, since it is larger than the sum of its proper divisors (44548999).

256402489 is an equidigital number, since it uses as much as digits as its factorization.

256402489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990015.

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 256402489 is about 16012.5728413644. The cubic root of 256402489 is about 635.2930129316.

The spelling of 256402489 in words is "two hundred fifty-six million, four hundred two thousand, four hundred eighty-nine".