21456645104642 has 16 divisors (see below), whose sum is σ = 35111977440192. Its totient is φ = 9752713937520.

The previous prime is 21456645104563. The next prime is 21456645104659. The reversal of 21456645104642 is 24640154665412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14611673 + ... + 16012940.

It is an arithmetic number, because the mean of its divisors is an integer number (2194498590012).

Almost surely, 2^{21456645104642} is an apocalyptic number.

21456645104642 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21456645104642 is a deficient number, since it is larger than the sum of its proper divisors (13655332335550).

21456645104642 is a wasteful number, since it uses less digits than its factorization.

21456645104642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30656473.

The product of its (nonzero) digits is 5529600, while the sum is 50.

The spelling of 21456645104642 in words is "twenty-one trillion, four hundred fifty-six billion, six hundred forty-five million, one hundred four thousand, six hundred forty-two".