20778188340 has 864 divisors, whose sum is σ = 80750960640. Its totient is φ = 3962649600.

The previous prime is 20778188303. The next prime is 20778188407. The reversal of 20778188340 is 4388187702.

It is a happy number.

It is a super-2 number, since 2×20778188340² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20778188340.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 292650505 + ... + 292650575.

It is an arithmetic number, because the mean of its divisors is an integer number (93461760).

Almost surely, 2^20778188340 is an apocalyptic number.

20778188340 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 20778188340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40375480320).

20778188340 is an abundant number, since it is smaller than the sum of its proper divisors (59972772300).

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

20778188340 is a wasteful number, since it uses less digits than its factorization.

20778188340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173 (or 151 counting only the distinct ones).

The product of its (nonzero) digits is 602112, while the sum is 48.

The spelling of 20778188340 in words is "twenty billion, seven hundred seventy-eight million, one hundred eighty-eight thousand, three hundred forty".