1644844984542 has 24 divisors (see below), whose sum is σ = 3773467906416. Its totient is φ = 516029798976.

The previous prime is 1644844984507. The next prime is 1644844984543. The reversal of 1644844984542 is 2454894484461.

1644844984542 is a `hidden beast` number, since 1 + 6 + 4 + 4 + 8 + 4 + 4 + 9 + 84 + 542 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 1644844984542.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644844984543) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2687654898 + ... + 2687655509.

It is an arithmetic number, because the mean of its divisors is an integer number (157227829434).

Almost surely, 2^{1644844984542} is an apocalyptic number.

1644844984542 is an abundant number, since it is smaller than the sum of its proper divisors (2128622921874).

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

1644844984542 is a wasteful number, since it uses less digits than its factorization.

1644844984542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5375310432 (or 5375310429 counting only the distinct ones).

The product of its digits is 141557760, while the sum is 63.

The spelling of 1644844984542 in words is "one trillion, six hundred forty-four billion, eight hundred forty-four million, nine hundred eighty-four thousand, five hundred forty-two".