256507244213345 has 4 divisors (see below), whose sum is σ = 307808693056020. Its totient is φ = 205205795370672.

The previous prime is 256507244213317. The next prime is 256507244213351. The reversal of 256507244213345 is 543312442705652.

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 2 ways, for example, as 97849942799569 + 158657301413776 = 9891913^2 + 12595924^2 .

It is a cyclic number.

It is not a de Polignac number, because 256507244213345 - 2⁸ = 256507244213089 is a prime.

It is a super-2 number, since 2×256507244213345² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25650724421330 + ... + 25650724421339.

It is an arithmetic number, because the mean of its divisors is an integer number (76952173264005).

Almost surely, 2^{256507244213345} is an apocalyptic number.

It is an amenable number.

256507244213345 is a deficient number, since it is larger than the sum of its proper divisors (51301448842675).

256507244213345 is an equidigital number, since it uses as much as digits as its factorization.

256507244213345 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51301448842674.

The product of its (nonzero) digits is 24192000, while the sum is 53.

Adding to 256507244213345 its reverse (543312442705652), we get a palindrome (799819686918997).

The spelling of 256507244213345 in words is "two hundred fifty-six trillion, five hundred seven billion, two hundred forty-four million, two hundred thirteen thousand, three hundred forty-five".