256816390 has 16 divisors (see below), whose sum is σ = 482368608. Its totient is φ = 98260096.

The previous prime is 256816387. The next prime is 256816397. The reversal of 256816390 is 93618652.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256816397) 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, 558067 + ... + 558526.

It is an arithmetic number, because the mean of its divisors is an integer number (30148038).

Almost surely, 2^256816390 is an apocalyptic number.

256816390 is a deficient number, since it is larger than the sum of its proper divisors (225552218).

256816390 is a wasteful number, since it uses less digits than its factorization.

256816390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1116623.

The product of its (nonzero) digits is 77760, while the sum is 40.

The square root of 256816390 is about 16025.4918801265. The cubic root of 256816390 is about 635.6346724475.

The spelling of 256816390 in words is "two hundred fifty-six million, eight hundred sixteen thousand, three hundred ninety".