256633789634 has 4 divisors (see below), whose sum is σ = 384950684454. Its totient is φ = 128316894816.

The previous prime is 256633789591. The next prime is 256633789639. The reversal of 256633789634 is 436987336652.

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., 198840187225 + 57793602409 = 445915^2 + 240403^2 .

It is not an unprimeable number, because it can be changed into a prime (256633789639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64158447407 + ... + 64158447410.

Almost surely, 2^256633789634 is an apocalyptic number.

256633789634 is a deficient number, since it is larger than the sum of its proper divisors (128316894820).

256633789634 is a wasteful number, since it uses less digits than its factorization.

256633789634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128316894819.

The product of its digits is 117573120, while the sum is 62.

The spelling of 256633789634 in words is "two hundred fifty-six billion, six hundred thirty-three million, seven hundred eighty-nine thousand, six hundred thirty-four".