256947551 has 8 divisors (see below), whose sum is σ = 299195424. Its totient is φ = 216084960.

The previous prime is 256947547. The next prime is 256947577. The reversal of 256947551 is 155749652.

It is a happy number.

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

It is not a de Polignac number, because 256947551 - 2² = 256947547 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 (256947521) 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 in 7 ways as a sum of consecutive naturals, for example, 345920 + ... + 346661.

It is an arithmetic number, because the mean of its divisors is an integer number (37399428).

Almost surely, 2^256947551 is an apocalyptic number.

256947551 is a deficient number, since it is larger than the sum of its proper divisors (42247873).

256947551 is an equidigital number, since it uses as much as digits as its factorization.

256947551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 692641.

The product of its digits is 378000, while the sum is 44.

The square root of 256947551 is about 16029.5836190464. The cubic root of 256947551 is about 635.7428642577.

The spelling of 256947551 in words is "two hundred fifty-six million, nine hundred forty-seven thousand, five hundred fifty-one".