19440018 has 24 divisors (see below), whose sum is σ = 45360588. Its totient is φ = 5981472.

The previous prime is 19439977. The next prime is 19440019. The reversal of 19440018 is 81004491.

It can be written as a sum of positive squares in 2 ways, for example, as 18688329 + 751689 = 4323^2 + 867^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19439973 and 19440000.

It is not an unprimeable number, because it can be changed into a prime (19440019) 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, 41305 + ... + 41772.

Almost surely, 2^19440018 is an apocalyptic number.

19440018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

19440018 is an abundant number, since it is smaller than the sum of its proper divisors (25920570).

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

19440018 is a wasteful number, since it uses less digits than its factorization.

19440018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83098 (or 83095 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 19440018 is about 4409.0835782507. The cubic root of 19440018 is about 268.8843677824.

The spelling of 19440018 in words is "nineteen million, four hundred forty thousand, eighteen".