1221203125 has 14 divisors (see below), whose sum is σ = 1526503898. Its totient is φ = 976950000.

The previous prime is 1221203117. The next prime is 1221203129. The reversal of 1221203125 is 5213021221.

It can be written as a sum of positive squares in 7 ways, for example, as 1050926724 + 170276401 = 32418^2 + 13049^2 .

It is not a de Polignac number, because 1221203125 - 2³ = 1221203117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221203129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 23454 + ... + 54703.

Almost surely, 2^1221203125 is an apocalyptic number.

It is an amenable number.

1221203125 is a deficient number, since it is larger than the sum of its proper divisors (305300773).

1221203125 is an frugal number, since it uses more digits than its factorization.

1221203125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78187 (or 78162 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 1221203125 is about 34945.7168333975. The cubic root of 1221203125 is about 1068.8808647023.

Adding to 1221203125 its reverse (5213021221), we get a palindrome (6434224346).

The spelling of 1221203125 in words is "one billion, two hundred twenty-one million, two hundred three thousand, one hundred twenty-five".