19881420 has 96 divisors (see below), whose sum is σ = 60963840. Its totient is φ = 4811520.

The previous prime is 19881419. The next prime is 19881427. The reversal of 19881420 is 2418891.

It is a super-2 number, since 2×19881420² = 790541722432800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19881427) 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, 55201 + ... + 55559.

It is an arithmetic number, because the mean of its divisors is an integer number (635040).

Almost surely, 2^19881420 is an apocalyptic number.

19881420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19881420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30481920).

19881420 is an abundant number, since it is smaller than the sum of its proper divisors (41082420).

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

19881420 is a wasteful number, since it uses less digits than its factorization.

19881420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455 (or 453 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 19881420 is about 4458.8585983411. The cubic root of 19881420 is about 270.9042385291.

It can be divided in two parts, 19881 and 420, that added together give a triangular number (20301 = T₂₀₁).

The spelling of 19881420 in words is "nineteen million, eight hundred eighty-one thousand, four hundred twenty".