1221130311 has 16 divisors (see below), whose sum is σ = 1644854400. Its totient is φ = 805788000.

The previous prime is 1221130291. The next prime is 1221130321. The reversal of 1221130311 is 1130311221.

It is a happy number.

It is not a de Polignac number, because 1221130311 - 2¹¹ = 1221128263 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221130321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117765 + ... + 127713.

It is an arithmetic number, because the mean of its divisors is an integer number (102803400).

Almost surely, 2^1221130311 is an apocalyptic number.

1221130311 is a deficient number, since it is larger than the sum of its proper divisors (423724089).

1221130311 is a wasteful number, since it uses less digits than its factorization.

1221130311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10366.

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

The square root of 1221130311 is about 34944.6750020658. The cubic root of 1221130311 is about 1068.8596203418.

Adding to 1221130311 its reverse (1130311221), we get a palindrome (2351441532).

The spelling of 1221130311 in words is "one billion, two hundred twenty-one million, one hundred thirty thousand, three hundred eleven".