19782120 has 64 divisors (see below), whose sum is σ = 59641920. Its totient is φ = 5249024.

The previous prime is 19782109. The next prime is 19782121. The reversal of 19782120 is 2128791.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (19782121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42127 + ... + 42593.

It is an arithmetic number, because the mean of its divisors is an integer number (931905).

Almost surely, 2^19782120 is an apocalyptic number.

19782120 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 19782120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29820960).

19782120 is an abundant number, since it is smaller than the sum of its proper divisors (39859800).

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

19782120 is a wasteful number, since it uses less digits than its factorization.

19782120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834 (or 830 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 30.

The square root of 19782120 is about 4447.7095228893. The cubic root of 19782120 is about 270.4524649315.

The spelling of 19782120 in words is "nineteen million, seven hundred eighty-two thousand, one hundred twenty".