20720903744 has 56 divisors (see below), whose sum is σ = 42038854200. Its totient is φ = 10129793024.

The previous prime is 20720903743. The next prime is 20720903761. The reversal of 20720903744 is 44730902702.

It can be written as a sum of positive squares in 4 ways, for example, as 15346254400 + 5374649344 = 123880^2 + 73312^2 .

It is a super-2 number, since 2×20720903744² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20720903698 and 20720903707.

It is not an unprimeable number, because it can be changed into a prime (20720903743) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 983432 + ... + 1004280.

It is an arithmetic number, because the mean of its divisors is an integer number (750693825).

Almost surely, 2^20720903744 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20720903744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21019427100).

20720903744 is an abundant number, since it is smaller than the sum of its proper divisors (21317950456).

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

20720903744 is a wasteful number, since it uses less digits than its factorization.

20720903744 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21207 (or 21197 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 38.

The spelling of 20720903744 in words is "twenty billion, seven hundred twenty million, nine hundred three thousand, seven hundred forty-four".