256723835506 has 4 divisors (see below), whose sum is σ = 385085753262. Its totient is φ = 128361917752.

The previous prime is 256723835477. The next prime is 256723835507. The reversal of 256723835506 is 605538327652.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 198082854225 + 58640981281 = 445065^2 + 242159^2 .

It is not an unprimeable number, because it can be changed into a prime (256723835507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64180958875 + ... + 64180958878.

Almost surely, 2^256723835506 is an apocalyptic number.

256723835506 is a deficient number, since it is larger than the sum of its proper divisors (128361917756).

256723835506 is a wasteful number, since it uses less digits than its factorization.

256723835506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128361917755.

The product of its (nonzero) digits is 9072000, while the sum is 52.

The spelling of 256723835506 in words is "two hundred fifty-six billion, seven hundred twenty-three million, eight hundred thirty-five thousand, five hundred six".