19685920 has 48 divisors (see below), whose sum is σ = 47293848. Its totient is φ = 7741440.

The previous prime is 19685917. The next prime is 19685921. The reversal of 19685920 is 2958691.

It can be written as a sum of positive squares in 4 ways, for example, as 13868176 + 5817744 = 3724^2 + 2412^2 .

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (19685921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8752 + ... + 10768.

Almost surely, 2^19685920 is an apocalyptic number.

19685920 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 19685920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23646924).

19685920 is an abundant number, since it is smaller than the sum of its proper divisors (27607928).

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

19685920 is a wasteful number, since it uses less digits than its factorization.

19685920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2093 (or 2085 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 40.

The square root of 19685920 is about 4436.8817879227. The cubic root of 19685920 is about 270.0133509630.

The spelling of 19685920 in words is "nineteen million, six hundred eighty-five thousand, nine hundred twenty".