1221403145 has 8 divisors (see below), whose sum is σ = 1480794504. Its totient is φ = 967048704.

The previous prime is 1221403133. The next prime is 1221403153. The reversal of 1221403145 is 5413041221.

It can be written as a sum of positive squares in 4 ways, for example, as 70090384 + 1151312761 = 8372^2 + 33931^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221403145 - 2⁴ = 1221403129 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221403145.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1258694 + ... + 1259663.

It is an arithmetic number, because the mean of its divisors is an integer number (185099313).

Almost surely, 2^1221403145 is an apocalyptic number.

It is an amenable number.

1221403145 is a deficient number, since it is larger than the sum of its proper divisors (259391359).

1221403145 is an equidigital number, since it uses as much as digits as its factorization.

1221403145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2518459.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 1221403145 is about 34948.5785833988. The cubic root of 1221403145 is about 1068.9392185979.

Adding to 1221403145 its reverse (5413041221), we get a palindrome (6634444366).

The spelling of 1221403145 in words is "one billion, two hundred twenty-one million, four hundred three thousand, one hundred forty-five".