19821145444 has 24 divisors (see below), whose sum is σ = 36741296088. Its totient is φ = 9324072960.

The previous prime is 19821145433. The next prime is 19821145451. The reversal of 19821145444 is 44454112891.

It can be written as a sum of positive squares in 4 ways, for example, as 14911340544 + 4909804900 = 122112^2 + 70070^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 19821145444.

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, 130764 + ... + 238204.

It is an arithmetic number, because the mean of its divisors is an integer number (1530887337).

Almost surely, 2^19821145444 is an apocalyptic number.

It is an amenable number.

19821145444 is a deficient number, since it is larger than the sum of its proper divisors (16920150644).

19821145444 is a wasteful number, since it uses less digits than its factorization.

19821145444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110175 (or 110173 counting only the distinct ones).

The product of its digits is 184320, while the sum is 43.

The spelling of 19821145444 in words is "nineteen billion, eight hundred twenty-one million, one hundred forty-five thousand, four hundred forty-four".