20305711920 has 640 divisors, whose sum is σ = 76135127040. Its totient is φ = 4428103680.

The previous prime is 20305711913. The next prime is 20305711969. The reversal of 20305711920 is 2911750302.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 72262180 + ... + 72262460.

It is an arithmetic number, because the mean of its divisors is an integer number (118961136).

Almost surely, 2^20305711920 is an apocalyptic number.

20305711920 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 20305711920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38067563520).

20305711920 is an abundant number, since it is smaller than the sum of its proper divisors (55829415120).

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

20305711920 is a wasteful number, since it uses less digits than its factorization.

20305711920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 399 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 30.

The spelling of 20305711920 in words is "twenty billion, three hundred five million, seven hundred eleven thousand, nine hundred twenty".