20011911920 has 480 divisors, whose sum is σ = 64307312640. Its totient is φ = 5621391360.

The previous prime is 20011911919. The next prime is 20011911923. The reversal of 20011911920 is 2911911002.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a self number, because there is not a number n which added to its sum of digits gives 20011911920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20011911923) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 48928676 + ... + 48929084.

It is an arithmetic number, because the mean of its divisors is an integer number (133973568).

Almost surely, 2^20011911920 is an apocalyptic number.

20011911920 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 20011911920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32153656320).

20011911920 is an abundant number, since it is smaller than the sum of its proper divisors (44295400720).

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

20011911920 is a wasteful number, since it uses less digits than its factorization.

20011911920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 513 (or 494 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 20011911920 in words is "twenty billion, eleven million, nine hundred eleven thousand, nine hundred twenty".