19787920 has 80 divisors (see below), whose sum is σ = 48568320. Its totient is φ = 7488000.

The previous prime is 19787917. The next prime is 19787923. The reversal of 19787920 is 2978791.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (19787917) and next prime (19787923).

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (19787923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 195870 + ... + 195970.

It is an arithmetic number, because the mean of its divisors is an integer number (607104).

Almost surely, 2^19787920 is an apocalyptic number.

19787920 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 19787920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24284160).

19787920 is an abundant number, since it is smaller than the sum of its proper divisors (28780400).

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

19787920 is a wasteful number, since it uses less digits than its factorization.

19787920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224 (or 218 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 43.

The square root of 19787920 is about 4448.3614961017. The cubic root of 19787920 is about 270.4788940337.

The spelling of 19787920 in words is "nineteen million, seven hundred eighty-seven thousand, nine hundred twenty".