19479978 has 96 divisors (see below), whose sum is σ = 51916800. Its totient is φ = 5155488.

The previous prime is 19479947. The next prime is 19479979. The reversal of 19479978 is 87997491.

Its product of digits (1143072) is a multiple of the sum of its prime factors (216).

It is not an unprimeable number, because it can be changed into a prime (19479979) 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 47 ways as a sum of consecutive naturals, for example, 189075 + ... + 189177.

It is an arithmetic number, because the mean of its divisors is an integer number (540800).

Almost surely, 2^19479978 is an apocalyptic number.

19479978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19479978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25958400).

19479978 is an abundant number, since it is smaller than the sum of its proper divisors (32436822).

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

19479978 is a wasteful number, since it uses less digits than its factorization.

19479978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216 (or 213 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The square root of 19479978 is about 4413.6128058542. The cubic root of 19479978 is about 269.0684771058.

The spelling of 19479978 in words is "nineteen million, four hundred seventy-nine thousand, nine hundred seventy-eight".