20840380340 has 72 divisors (see below), whose sum is σ = 47464185888. Its totient is φ = 7682912640.

The previous prime is 20840380333. The next prime is 20840380409. The reversal of 20840380340 is 4308304802.

It is a junction number, because it is equal to n+sod(n) for n = 20840380297 and 20840380306.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2331119 + ... + 2340041.

It is an arithmetic number, because the mean of its divisors is an integer number (659224804).

Almost surely, 2^20840380340 is an apocalyptic number.

20840380340 is a gapful number since it is divisible by the number (20) 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 20840380340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23732092944).

20840380340 is an abundant number, since it is smaller than the sum of its proper divisors (26623805548).

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

20840380340 is a wasteful number, since it uses less digits than its factorization.

20840380340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9649 (or 9634 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 32.

The spelling of 20840380340 in words is "twenty billion, eight hundred forty million, three hundred eighty thousand, three hundred forty".