20123231132420 has 96 divisors (see below), whose sum is σ = 45968167845600. Its totient is φ = 7355347513344.

The previous prime is 20123231132401. The next prime is 20123231132423. The reversal of 20123231132420 is 2423113232102.

It can be written as a sum of positive squares in 16 ways, for example, as 14044925494336 + 6078305638084 = 3747656^2 + 2465422^2 .

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 20123231132420.

It is not an unprimeable number, because it can be changed into a prime (20123231132423) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 31337936 + ... + 31973624.

It is an arithmetic number, because the mean of its divisors is an integer number (478835081725).

Almost surely, 2^{20123231132420} is an apocalyptic number.

20123231132420 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 20123231132420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22984083922800).

20123231132420 is an abundant number, since it is smaller than the sum of its proper divisors (25844936713180).

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

20123231132420 is a wasteful number, since it uses less digits than its factorization.

20123231132420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636937 (or 636935 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 26.

Adding to 20123231132420 its reverse (2423113232102), we get a palindrome (22546344364522).

The spelling of 20123231132420 in words is "twenty trillion, one hundred twenty-three billion, two hundred thirty-one million, one hundred thirty-two thousand, four hundred twenty".