256705642 has 8 divisors (see below), whose sum is σ = 385279776. Its totient is φ = 128279052.

The previous prime is 256705619. The next prime is 256705663. The reversal of 256705642 is 246507652.

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

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 32428 + ... + 39559.

It is an arithmetic number, because the mean of its divisors is an integer number (48159972).

Almost surely, 2^256705642 is an apocalyptic number.

256705642 is a deficient number, since it is larger than the sum of its proper divisors (128574134).

256705642 is a wasteful number, since it uses less digits than its factorization.

256705642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73772.

The product of its (nonzero) digits is 100800, while the sum is 37.

The square root of 256705642 is about 16022.0361377698. The cubic root of 256705642 is about 635.5432901827.

The spelling of 256705642 in words is "two hundred fifty-six million, seven hundred five thousand, six hundred forty-two".