256121606242 has 16 divisors (see below), whose sum is σ = 389489075712. Its totient is φ = 126292309920.

The previous prime is 256121606179. The next prime is 256121606243. The reversal of 256121606242 is 242606121652.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (256121606243) 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, 1265203 + ... + 1453609.

It is an arithmetic number, because the mean of its divisors is an integer number (24343067232).

Almost surely, 2^256121606242 is an apocalyptic number.

256121606242 is a deficient number, since it is larger than the sum of its proper divisors (133367469470).

256121606242 is a wasteful number, since it uses less digits than its factorization.

256121606242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197793.

The product of its (nonzero) digits is 69120, while the sum is 37.

Adding to 256121606242 its reverse (242606121652), we get a palindrome (498727727894).

The spelling of 256121606242 in words is "two hundred fifty-six billion, one hundred twenty-one million, six hundred six thousand, two hundred forty-two".