19405223640 has 384 divisors, whose sum is σ = 72727200000. Its totient is φ = 4437918720.

The previous prime is 19405223633. The next prime is 19405223641. The reversal of 19405223640 is 4632250491.

It is a happy number.

19405223640 is a `hidden beast` number, since 1 + 9 + 4 + 0 + 5 + 2 + 2 + 3 + 640 = 666.

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 = 19405223595 and 19405223604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19405223641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 26258391 + ... + 26259129.

It is an arithmetic number, because the mean of its divisors is an integer number (189393750).

Almost surely, 2^19405223640 is an apocalyptic number.

19405223640 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 19405223640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36363600000).

19405223640 is an abundant number, since it is smaller than the sum of its proper divisors (53321976360).

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

19405223640 is a wasteful number, since it uses less digits than its factorization.

19405223640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135 (or 1128 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 19405223640 in words is "nineteen billion, four hundred five million, two hundred twenty-three thousand, six hundred forty".