19881738 has 48 divisors (see below), whose sum is σ = 46702656. Its totient is φ = 6088320.

The previous prime is 19881727. The next prime is 19881751. The reversal of 19881738 is 83718891.

It is a junction number, because it is equal to n+sod(n) for n = 19881693 and 19881702.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12403 + ... + 13913.

It is an arithmetic number, because the mean of its divisors is an integer number (972972).

Almost surely, 2^19881738 is an apocalyptic number.

19881738 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 19881738, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23351328).

19881738 is an abundant number, since it is smaller than the sum of its proper divisors (26820918).

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

19881738 is a wasteful number, since it uses less digits than its factorization.

19881738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1579 (or 1576 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 19881738 is about 4458.8942575486. The cubic root of 19881738 is about 270.9056828775.

The spelling of 19881738 in words is "nineteen million, eight hundred eighty-one thousand, seven hundred thirty-eight".