256321506 has 16 divisors (see below), whose sum is σ = 585877824. Its totient is φ = 73234704.

The previous prime is 256321501. The next prime is 256321511. The reversal of 256321506 is 605123652.

256321506 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (256321501) and next prime (256321511).

It is not an unprimeable number, because it can be changed into a prime (256321501) 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, 3051405 + ... + 3051488.

It is an arithmetic number, because the mean of its divisors is an integer number (36617364).

Almost surely, 2^256321506 is an apocalyptic number.

256321506 is an abundant number, since it is smaller than the sum of its proper divisors (329556318).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256321506 is a wasteful number, since it uses less digits than its factorization.

256321506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6102905.

The product of its (nonzero) digits is 10800, while the sum is 30.

The square root of 256321506 is about 16010.0439099960. The cubic root of 256321506 is about 635.2261215483.

The spelling of 256321506 in words is "two hundred fifty-six million, three hundred twenty-one thousand, five hundred six".