256401162066 has 128 divisors (see below), whose sum is σ = 625205329920. Its totient is φ = 68430615552.

The previous prime is 256401162011. The next prime is 256401162071. The reversal of 256401162066 is 660261104652.

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 63 ways as a sum of consecutive naturals, for example, 88810875 + ... + 88813761.

It is an arithmetic number, because the mean of its divisors is an integer number (4884416640).

Almost surely, 2^256401162066 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256401162066, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (312602664960).

256401162066 is an abundant number, since it is smaller than the sum of its proper divisors (368804167854).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256401162066 is a wasteful number, since it uses less digits than its factorization.

256401162066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3808.

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 256401162066 in words is "two hundred fifty-six billion, four hundred one million, one hundred sixty-two thousand, sixty-six".