256420396449424 has 45 divisors (see below), whose sum is σ = 499348441204617. Its totient is φ = 127559584671552.

The previous prime is 256420396449419. The next prime is 256420396449431. The reversal of 256420396449424 is 424944693024652.

The square root of 256420396449424 is 16013132.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 53221985715600 + 203198410733824 = 7295340^2 + 14254768^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 12746443014 + ... + 12746463130.

Almost surely, 2^{256420396449424} is an apocalyptic number.

256420396449424 is the 16013132-nd square number.

It is an amenable number.

256420396449424 is a deficient number, since it is larger than the sum of its proper divisors (242928044755193).

256420396449424 is an frugal number, since it uses more digits than its factorization.

256420396449424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40640 (or 20318 counting only the distinct ones).

The product of its (nonzero) digits is 358318080, while the sum is 64.

The spelling of 256420396449424 in words is "two hundred fifty-six trillion, four hundred twenty billion, three hundred ninety-six million, four hundred forty-nine thousand, four hundred twenty-four".