20051213041720 has 256 divisors, whose sum is σ = 53679172884480. Its totient is φ = 6597980928000.

The previous prime is 20051213041693. The next prime is 20051213041723. The reversal of 20051213041720 is 2714031215002.

It is a super-2 number, since 2×20051213041720² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20051213041723) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 743974245 + ... + 744001195.

It is an arithmetic number, because the mean of its divisors is an integer number (209684269080).

Almost surely, 2^{20051213041720} is an apocalyptic number.

20051213041720 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 20051213041720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26839586442240).

20051213041720 is an abundant number, since it is smaller than the sum of its proper divisors (33627959842760).

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

20051213041720 is a wasteful number, since it uses less digits than its factorization.

20051213041720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28086 (or 28082 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 28.

Adding to 20051213041720 its reverse (2714031215002), we get a palindrome (22765244256722).

The spelling of 20051213041720 in words is "twenty trillion, fifty-one billion, two hundred thirteen million, forty-one thousand, seven hundred twenty".