20432120400 has 420 divisors, whose sum is σ = 75437788860. Its totient is φ = 5312563200.

The previous prime is 20432120393. The next prime is 20432120411. The reversal of 20432120400 is 402123402.

It can be written as a sum of positive squares in 6 ways, for example, as 6369955344 + 14062165056 = 79812^2 + 118584^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 11954746 + ... + 11956454.

It is an arithmetic number, because the mean of its divisors is an integer number (179613783).

Almost surely, 2^20432120400 is an apocalyptic number.

20432120400 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 20432120400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37718894430).

20432120400 is an abundant number, since it is smaller than the sum of its proper divisors (55005668460).

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

20432120400 is a wasteful number, since it uses less digits than its factorization.

20432120400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1786 (or 1760 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 20432120400 its reverse (402123402), we get a palindrome (20834243802).

The spelling of 20432120400 in words is "twenty billion, four hundred thirty-two million, one hundred twenty thousand, four hundred".