19394640 has 200 divisors, whose sum is σ = 69948648. Its totient is φ = 4976640.

The previous prime is 19394593. The next prime is 19394647. The reversal of 19394640 is 4649391.

19394640 is a `hidden beast` number, since 1 + 9 + 3 + 9 + 4 + 640 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 104976 + 19289664 = 324^2 + 4392^2 .

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

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 19394595 and 19394604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19394647) 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 39 ways as a sum of consecutive naturals, for example, 265644 + ... + 265716.

Almost surely, 2^19394640 is an apocalyptic number.

19394640 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 19394640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34974324).

19394640 is an abundant number, since it is smaller than the sum of its proper divisors (50554008).

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

19394640 is a wasteful number, since it uses less digits than its factorization.

19394640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The square root of 19394640 is about 4403.9346044191. The cubic root of 19394640 is about 268.6749897023.

The spelling of 19394640 in words is "nineteen million, three hundred ninety-four thousand, six hundred forty".