256644370416442 has 4 divisors (see below), whose sum is σ = 384966555624666. Its totient is φ = 128322185208220.

The previous prime is 256644370416439. The next prime is 256644370416457. The reversal of 256644370416442 is 244614073446652.

It is a happy number.

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., 249094850342121 + 7549520074321 = 15782739^2 + 2747639^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64161092604109 + ... + 64161092604112.

Almost surely, 2^{256644370416442} is an apocalyptic number.

256644370416442 is a deficient number, since it is larger than the sum of its proper divisors (128322185208224).

256644370416442 is a wasteful number, since it uses less digits than its factorization.

256644370416442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128322185208223.

The product of its (nonzero) digits is 92897280, while the sum is 58.

The spelling of 256644370416442 in words is "two hundred fifty-six trillion, six hundred forty-four billion, three hundred seventy million, four hundred sixteen thousand, four hundred forty-two".