18939450 has 48 divisors (see below), whose sum is σ = 48496896. Its totient is φ = 4886400.

The previous prime is 18939443. The next prime is 18939457. The reversal of 18939450 is 5493981.

It is an interprime number because it is at equal distance from previous prime (18939443) and next prime (18939457).

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 18939399 and 18939408.

It is not an unprimeable number, because it can be changed into a prime (18939457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2614 + ... + 6686.

It is an arithmetic number, because the mean of its divisors is an integer number (1010352).

Almost surely, 2^18939450 is an apocalyptic number.

18939450 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18939450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24248448).

18939450 is an abundant number, since it is smaller than the sum of its proper divisors (29557446).

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

18939450 is a wasteful number, since it uses less digits than its factorization.

18939450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4119 (or 4114 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 18939450 is about 4351.9478397610. The cubic root of 18939450 is about 266.5564040672.

The spelling of 18939450 in words is "eighteen million, nine hundred thirty-nine thousand, four hundred fifty".