19947438 has 64 divisors (see below), whose sum is σ = 51217920. Its totient is φ = 5636736.

The previous prime is 19947437. The next prime is 19947439. The reversal of 19947438 is 83474991.

It is an interprime number because it is at equal distance from previous prime (19947437) and next prime (19947439).

It is a junction number, because it is equal to n+sod(n) for n = 19947393 and 19947402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19947437) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42481 + ... + 42947.

It is an arithmetic number, because the mean of its divisors is an integer number (800280).

Almost surely, 2^19947438 is an apocalyptic number.

19947438 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 19947438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25608960).

19947438 is an abundant number, since it is smaller than the sum of its proper divisors (31270482).

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

19947438 is a wasteful number, since it uses less digits than its factorization.

19947438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 598 (or 592 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 19947438 is about 4466.2554785861. The cubic root of 19947438 is about 271.2037610098.

The spelling of 19947438 in words is "nineteen million, nine hundred forty-seven thousand, four hundred thirty-eight".