1200400128320 has 28 divisors (see below), whose sum is σ = 2858452806324. Its totient is φ = 480160051200.

The previous prime is 1200400128287. The next prime is 1200400128329. The reversal of 1200400128320 is 238210040021.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 882186805504 + 318213322816 = 939248^2 + 564104^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200400128329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1875624881 + ... + 1875625520.

Almost surely, 2^{1200400128320} is an apocalyptic number.

1200400128320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1200400128320 is an abundant number, since it is smaller than the sum of its proper divisors (1658052678004).

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

1200400128320 is an equidigital number, since it uses as much as digits as its factorization.

1200400128320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3751250418 (or 3751250408 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 1200400128320 its reverse (238210040021), we get a palindrome (1438610168341).

The spelling of 1200400128320 in words is "one trillion, two hundred billion, four hundred million, one hundred twenty-eight thousand, three hundred twenty".