20019920940 has 144 divisors (see below), whose sum is σ = 61450421760. Its totient is φ = 5275445760.

The previous prime is 20019920917. The next prime is 20019920941. The reversal of 20019920940 is 4902991002.

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 = 20019920895 and 20019920904.

It is not an unprimeable number, because it can be changed into a prime (20019920941) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5395806 + ... + 5399514.

It is an arithmetic number, because the mean of its divisors is an integer number (426739040).

Almost surely, 2^20019920940 is an apocalyptic number.

20019920940 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 20019920940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30725210880).

20019920940 is an abundant number, since it is smaller than the sum of its proper divisors (41430500820).

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

20019920940 is a wasteful number, since it uses less digits than its factorization.

20019920940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4072 (or 4067 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The spelling of 20019920940 in words is "twenty billion, nineteen million, nine hundred twenty thousand, nine hundred forty".