20280236661720 has 896 divisors, whose sum is σ = 79727263862400. Its totient is φ = 4545121517568.

The previous prime is 20280236661719. The next prime is 20280236661721. The reversal of 20280236661720 is 2716663208202.

It is an interprime number because it is at equal distance from previous prime (20280236661719) and next prime (20280236661721).

It is a super-2 number, since 2×20280236661720² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20280236661721) by changing a digit.

It is a polite number, since it can be written in 223 ways as a sum of consecutive naturals, for example, 2158156062 + ... + 2158165458.

It is an arithmetic number, because the mean of its divisors is an integer number (88981321275).

Almost surely, 2^{20280236661720} is an apocalyptic number.

20280236661720 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 20280236661720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39863631931200).

20280236661720 is an abundant number, since it is smaller than the sum of its proper divisors (59447027200680).

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

20280236661720 is a wasteful number, since it uses less digits than its factorization.

20280236661720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9639 (or 9620 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

Adding to 20280236661720 its reverse (2716663208202), we get a palindrome (22996899869922).

The spelling of 20280236661720 in words is "twenty trillion, two hundred eighty billion, two hundred thirty-six million, six hundred sixty-one thousand, seven hundred twenty".