19965240 has 96 divisors (see below), whose sum is σ = 67017600. Its totient is φ = 5149440.

The previous prime is 19965229. The next prime is 19965247. The reversal of 19965240 is 4256991.

It is a super-2 number, since 2×19965240² = 797221616515200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 19965195 and 19965204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19965247) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10266 + ... + 12054.

It is an arithmetic number, because the mean of its divisors is an integer number (698100).

Almost surely, 2^19965240 is an apocalyptic number.

19965240 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 19965240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33508800).

19965240 is an abundant number, since it is smaller than the sum of its proper divisors (47052360).

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

19965240 is a wasteful number, since it uses less digits than its factorization.

19965240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1837 (or 1830 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 19965240 is about 4468.2479787944. The cubic root of 19965240 is about 271.2844152076.

The spelling of 19965240 in words is "nineteen million, nine hundred sixty-five thousand, two hundred forty".