256203431138 has 6 divisors (see below), whose sum is σ = 384306220449. Its totient is φ = 128101357656.

The previous prime is 256203431137. The next prime is 256203431167. The reversal of 256203431138 is 831134302652.

It can be written as a sum of positive squares in 2 ways, for example, as 245874164449 + 10329266689 = 495857^2 + 101633^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=357913.

It is a super-3 number, since 3×256203431138³ (a number of 35 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (256203431131) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 536870 + ... + 894782.

Almost surely, 2^256203431138 is an apocalyptic number.

256203431138 is a deficient number, since it is larger than the sum of its proper divisors (128102789311).

256203431138 is an frugal number, since it uses more digits than its factorization.

256203431138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 715828 (or 357915 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 38.

The spelling of 256203431138 in words is "two hundred fifty-six billion, two hundred three million, four hundred thirty-one thousand, one hundred thirty-eight".