1212400305 has 80 divisors (see below), whose sum is σ = 2312879184. Its totient is φ = 605491200.

The previous prime is 1212400289. The next prime is 1212400307. The reversal of 1212400305 is 5030042121.

1212400305 is a `hidden beast` number, since 121 + 240 + 0 + 305 = 666.

1212400305 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 320123664 + 892276641 = 17892^2 + 29871^2 .

It is not a de Polignac number, because 1212400305 - 2⁴ = 1212400289 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1212400307) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2017005 + ... + 2017605.

Almost surely, 2^1212400305 is an apocalyptic number.

1212400305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1212400305 is a deficient number, since it is larger than the sum of its proper divisors (1100478879).

1212400305 is a wasteful number, since it uses less digits than its factorization.

1212400305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 928 (or 919 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 1212400305 is about 34819.5391267604. The cubic root of 1212400305 is about 1066.3063912943.

Adding to 1212400305 its reverse (5030042121), we get a palindrome (6242442426).

The spelling of 1212400305 in words is "one billion, two hundred twelve million, four hundred thousand, three hundred five".