1200120400 has 30 divisors (see below), whose sum is σ = 2883290222. Its totient is φ = 480048000.

The previous prime is 1200120349. The next prime is 1200120401. The reversal of 1200120400 is 40210021.

It can be written as a sum of positive squares in 3 ways, for example, as 168169024 + 1031951376 = 12968^2 + 32124^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200120401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1499751 + ... + 1500550.

Almost surely, 2^1200120400 is an apocalyptic number.

1200120400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1200120400 is an abundant number, since it is smaller than the sum of its proper divisors (1683169822).

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

1200120400 is a wasteful number, since it uses less digits than its factorization.

1200120400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3000319 (or 3000308 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 1200120400 is about 34642.7539320996. The cubic root of 1200120400 is about 1062.6941080195.

Adding to 1200120400 its reverse (40210021), we get a palindrome (1240330421).

The spelling of 1200120400 in words is "one billion, two hundred million, one hundred twenty thousand, four hundred".