20781224320 has 128 divisors (see below), whose sum is σ = 53071122240. Its totient is φ = 7753826304.

The previous prime is 20781224287. The next prime is 20781224357. The reversal of 20781224320 is 2342218702.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1220989 + ... + 1237891.

Almost surely, 2^20781224320 is an apocalyptic number.

20781224320 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 20781224320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26535561120).

20781224320 is an abundant number, since it is smaller than the sum of its proper divisors (32289897920).

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

20781224320 is a wasteful number, since it uses less digits than its factorization.

20781224320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17052 (or 17040 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 31.

The spelling of 20781224320 in words is "twenty billion, seven hundred eighty-one million, two hundred twenty-four thousand, three hundred twenty".