1221103131 has 4 divisors (see below), whose sum is σ = 1628137512. Its totient is φ = 814068752.

The previous prime is 1221103111. The next prime is 1221103133. The reversal of 1221103131 is 1313011221.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221103131 - 2⁶ = 1221103067 is a prime.

It is a super-2 number, since 2×1221103131² = 2982185713076006322, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221103131.

It is not an unprimeable number, because it can be changed into a prime (1221103133) 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 3 ways as a sum of consecutive naturals, for example, 203517186 + ... + 203517191.

It is an arithmetic number, because the mean of its divisors is an integer number (407034378).

Almost surely, 2^1221103131 is an apocalyptic number.

1221103131 is a deficient number, since it is larger than the sum of its proper divisors (407034381).

1221103131 is an equidigital number, since it uses as much as digits as its factorization.

1221103131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407034380.

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1221103131 is about 34944.2860994469. The cubic root of 1221103131 is about 1068.8516900333.

Adding to 1221103131 its reverse (1313011221), we get a palindrome (2534114352).

The spelling of 1221103131 in words is "one billion, two hundred twenty-one million, one hundred three thousand, one hundred thirty-one".