19965140 has 48 divisors (see below), whose sum is σ = 47818512. Its totient is φ = 6936576.

The previous prime is 19965133. The next prime is 19965149. The reversal of 19965140 is 4156991.

It can be written as a sum of positive squares in 8 ways, for example, as 4251844 + 15713296 = 2062^2 + 3964^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 19965140.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19965149) 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, 2162 + ... + 6678.

It is an arithmetic number, because the mean of its divisors is an integer number (996219).

Almost surely, 2^19965140 is an apocalyptic number.

19965140 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 19965140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23909256).

19965140 is an abundant number, since it is smaller than the sum of its proper divisors (27853372).

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

19965140 is a wasteful number, since it uses less digits than its factorization.

19965140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4556 (or 4554 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 19965140 is about 4468.2367887121. The cubic root of 19965140 is about 271.2839622790.

The spelling of 19965140 in words is "nineteen million, nine hundred sixty-five thousand, one hundred forty".