20123130400 has 72 divisors (see below), whose sum is σ = 49560554484. Its totient is φ = 7977984000.

The previous prime is 20123130389. The next prime is 20123130407. The reversal of 20123130400 is 403132102.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 75968656 + 20047161744 = 8716^2 + 141588^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is not an unprimeable number, because it can be changed into a prime (20123130407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20901 + ... + 201700.

Almost surely, 2^20123130400 is an apocalyptic number.

20123130400 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 20123130400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24780277242).

20123130400 is an abundant number, since it is smaller than the sum of its proper divisors (29437424084).

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

20123130400 is a wasteful number, since it uses less digits than its factorization.

20123130400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222734 (or 222721 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 20123130400 its reverse (403132102), we get a palindrome (20526262502).

The spelling of 20123130400 in words is "twenty billion, one hundred twenty-three million, one hundred thirty thousand, four hundred".