1321220121 has 32 divisors (see below), whose sum is σ = 1951219200. Its totient is φ = 790041600.

The previous prime is 1321220111. The next prime is 1321220123. The reversal of 1321220121 is 1210221231.

It is not a de Polignac number, because 1321220121 - 2⁹ = 1321219609 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321220121.

It is not an unprimeable number, because it can be changed into a prime (1321220123) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 431805 + ... + 434853.

It is an arithmetic number, because the mean of its divisors is an integer number (60975600).

Almost surely, 2^1321220121 is an apocalyptic number.

It is an amenable number.

1321220121 is a deficient number, since it is larger than the sum of its proper divisors (629999079).

1321220121 is a wasteful number, since it uses less digits than its factorization.

1321220121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3377.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1321220121 is about 36348.5917333808. The cubic root of 1321220121 is about 1097.2991926478.

Adding to 1321220121 its reverse (1210221231), we get a palindrome (2531441352).

It can be divided in two parts, 13212 and 20121, that added together give a palindrome (33333).

The spelling of 1321220121 in words is "one billion, three hundred twenty-one million, two hundred twenty thousand, one hundred twenty-one".