18519421444 has 24 divisors (see below), whose sum is σ = 34465276440. Its totient is φ = 8676957696.

The previous prime is 18519421423. The next prime is 18519421447. The reversal of 18519421444 is 44412491581.

It can be written as a sum of positive squares in 4 ways, for example, as 9473128900 + 9046292544 = 97330^2 + 95112^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18519421444.

It is not an unprimeable number, because it can be changed into a prime (18519421447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 579067 + ... + 610210.

It is an arithmetic number, because the mean of its divisors is an integer number (1436053185).

Almost surely, 2^18519421444 is an apocalyptic number.

It is an amenable number.

18519421444 is a deficient number, since it is larger than the sum of its proper divisors (15945854996).

18519421444 is a wasteful number, since it uses less digits than its factorization.

18519421444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1189527 (or 1189525 counting only the distinct ones).

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

The spelling of 18519421444 in words is "eighteen billion, five hundred nineteen million, four hundred twenty-one thousand, four hundred forty-four".