256516544643321 has 24 divisors (see below), whose sum is σ = 354594304078560. Its totient is φ = 164940838969984.

The previous prime is 256516544643287. The next prime is 256516544643341. The reversal of 256516544643321 is 123346445615652.

256516544643321 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 256516544643321 - 2¹³ = 256516544635129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (256516544643341) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 50938311 + ... + 55747148.

It is an arithmetic number, because the mean of its divisors is an integer number (14774762669940).

Almost surely, 2^{256516544643321} is an apocalyptic number.

It is an amenable number.

256516544643321 is a deficient number, since it is larger than the sum of its proper divisors (98077759435239).

256516544643321 is a wasteful number, since it uses less digits than its factorization.

256516544643321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106686473 (or 106686444 counting only the distinct ones).

The product of its digits is 62208000, while the sum is 57.

The spelling of 256516544643321 in words is "two hundred fifty-six trillion, five hundred sixteen billion, five hundred forty-four million, six hundred forty-three thousand, three hundred twenty-one".