19994040 has 288 divisors, whose sum is σ = 78427440. Its totient is φ = 4561920.

The previous prime is 19994033. The next prime is 19994047. The reversal of 19994040 is 4049991.

It is an interprime number because it is at equal distance from previous prime (19994033) and next prime (19994047).

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 = 19993986 and 19994004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19994047) 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 71 ways as a sum of consecutive naturals, for example, 1176112 + ... + 1176128.

Almost surely, 2^19994040 is an apocalyptic number.

19994040 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 19994040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39213720).

19994040 is an abundant number, since it is smaller than the sum of its proper divisors (58433400).

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

19994040 is a wasteful number, since it uses less digits than its factorization.

19994040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65 (or 38 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 19994040 is about 4471.4695570919. The cubic root of 19994040 is about 271.4147957657.

Subtracting from 19994040 its reverse (4049991), we obtain a square (15944049 = 3993²).

The spelling of 19994040 in words is "nineteen million, nine hundred ninety-four thousand, forty".