256722387 has 8 divisors (see below), whose sum is σ = 342476736. Its totient is φ = 171058152.

The previous prime is 256722383. The next prime is 256722409. The reversal of 256722387 is 783227652.

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

It is not a de Polignac number, because 256722387 - 2² = 256722383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256722383) 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, 15573 + ... + 27494.

It is an arithmetic number, because the mean of its divisors is an integer number (42809592).

Almost surely, 2^256722387 is an apocalyptic number.

256722387 is a deficient number, since it is larger than the sum of its proper divisors (85754349).

256722387 is a wasteful number, since it uses less digits than its factorization.

256722387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45057.

The product of its digits is 282240, while the sum is 42.

The square root of 256722387 is about 16022.5586907959. The cubic root of 256722387 is about 635.5571087870.

The spelling of 256722387 in words is "two hundred fifty-six million, seven hundred twenty-two thousand, three hundred eighty-seven".