256780247 has 8 divisors (see below), whose sum is σ = 261936000. Its totient is φ = 251663544.

The previous prime is 256780217. The next prime is 256780273. The reversal of 256780247 is 742087652.

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 256780247 - 2¹² = 256776151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256780207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3704 + ... + 22962.

It is an arithmetic number, because the mean of its divisors is an integer number (32742000).

Almost surely, 2^256780247 is an apocalyptic number.

256780247 is a deficient number, since it is larger than the sum of its proper divisors (5155753).

256780247 is a wasteful number, since it uses less digits than its factorization.

256780247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19525.

The product of its (nonzero) digits is 188160, while the sum is 41.

The square root of 256780247 is about 16024.3641683531. The cubic root of 256780247 is about 635.6048524118.

The spelling of 256780247 in words is "two hundred fifty-six million, seven hundred eighty thousand, two hundred forty-seven".