1221420311 has 2 divisors, whose sum is σ = 1221420312. Its totient is φ = 1221420310.

The previous prime is 1221420271. The next prime is 1221420329. The reversal of 1221420311 is 1130241221.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1221420311 - 2²² = 1217226007 is a prime.

It is a super-2 number, since 2×1221420311² = 2983735152246673442, 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 1221420311.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221420331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610710155 + 610710156.

It is an arithmetic number, because the mean of its divisors is an integer number (610710156).

Almost surely, 2^1221420311 is an apocalyptic number.

1221420311 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221420311 is an equidigital number, since it uses as much as digits as its factorization.

1221420311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 1221420311 is about 34948.8241719232. The cubic root of 1221420311 is about 1068.9442263151.

Adding to 1221420311 its reverse (1130241221), we get a palindrome (2351661532).

The spelling of 1221420311 in words is "one billion, two hundred twenty-one million, four hundred twenty thousand, three hundred eleven".