1321221101 has 4 divisors (see below), whose sum is σ = 1321303104. Its totient is φ = 1321139100.

The previous prime is 1321221061. The next prime is 1321221103. The reversal of 1321221101 is 1011221231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321221101 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321221103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7955 + ... + 52016.

It is an arithmetic number, because the mean of its divisors is an integer number (330325776).

Almost surely, 2^1321221101 is an apocalyptic number.

It is an amenable number.

1321221101 is a deficient number, since it is larger than the sum of its proper divisors (82003).

1321221101 is an equidigital number, since it uses as much as digits as its factorization.

1321221101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82002.

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 1321221101 is about 36348.6052139556. The cubic root of 1321221101 is about 1097.2994639508.

Adding to 1321221101 its reverse (1011221231), we get a palindrome (2332442332).

The spelling of 1321221101 in words is "one billion, three hundred twenty-one million, two hundred twenty-one thousand, one hundred one".