256816867346 has 24 divisors (see below), whose sum is σ = 417184627860. Its totient is φ = 118517458176.

The previous prime is 256816867339. The next prime is 256816867357. The reversal of 256816867346 is 643768618652.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 157787700625 + 99029166721 = 397225^2 + 314689^2 .

It is a super-2 number, since 2×256816867346² (a number of 24 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3345086 + ... + 3420998.

Almost surely, 2^256816867346 is an apocalyptic number.

256816867346 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

256816867346 is a deficient number, since it is larger than the sum of its proper divisors (160367760514).

256816867346 is a wasteful number, since it uses less digits than its factorization.

256816867346 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85950 (or 85937 counting only the distinct ones).

The product of its digits is 69672960, while the sum is 62.

The spelling of 256816867346 in words is "two hundred fifty-six billion, eight hundred sixteen million, eight hundred sixty-seven thousand, three hundred forty-six".