18440473444 has 24 divisors (see below), whose sum is σ = 34182298080. Its totient is φ = 8674521216.

The previous prime is 18440473391. The next prime is 18440473451. The reversal of 18440473444 is 44437404481.

It is a happy number.

It is a super-2 number, since 2×18440473444² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18440473444.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129819 + ... + 231805.

It is an arithmetic number, because the mean of its divisors is an integer number (1424262420).

Almost surely, 2^18440473444 is an apocalyptic number.

It is an amenable number.

18440473444 is a deficient number, since it is larger than the sum of its proper divisors (15741824636).

18440473444 is a wasteful number, since it uses less digits than its factorization.

18440473444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104667 (or 104665 counting only the distinct ones).

The product of its (nonzero) digits is 688128, while the sum is 43.

The spelling of 18440473444 in words is "eighteen billion, four hundred forty million, four hundred seventy-three thousand, four hundred forty-four".