1221211803 has 8 divisors (see below), whose sum is σ = 1860894208. Its totient is φ = 697835304.

The previous prime is 1221211801. The next prime is 1221211867. The reversal of 1221211803 is 3081121221.

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

It is not a de Polignac number, because 1221211803 - 2¹ = 1221211801 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 58152943 = 1221211803 / (1 + 2 + 2 + 1 + 2 + 1 + 1 + 8 + 0 + 3).

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 1221211803.

It is not an unprimeable number, because it can be changed into a prime (1221211801) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29076451 + ... + 29076492.

It is an arithmetic number, because the mean of its divisors is an integer number (232611776).

Almost surely, 2^1221211803 is an apocalyptic number.

1221211803 is a deficient number, since it is larger than the sum of its proper divisors (639682405).

1221211803 is an equidigital number, since it uses as much as digits as its factorization.

1221211803 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58152953.

The product of its (nonzero) digits is 192, while the sum is 21.

The square root of 1221211803 is about 34945.8409971773. The cubic root of 1221211803 is about 1068.8833965568.

The spelling of 1221211803 in words is "one billion, two hundred twenty-one million, two hundred eleven thousand, eight hundred three".