1221311310 has 16 divisors (see below), whose sum is σ = 2931147216. Its totient is φ = 325683008.

The previous prime is 1221311261. The next prime is 1221311341. The reversal of 1221311310 is 131131221.

It is a happy number.

It is a super-2 number, since 2×1221311310² = 2983202631867832200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221311310.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 20355159 + ... + 20355218.

It is an arithmetic number, because the mean of its divisors is an integer number (183196701).

Almost surely, 2^1221311310 is an apocalyptic number.

1221311310 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221311310 is an abundant number, since it is smaller than the sum of its proper divisors (1709835906).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221311310 is a wasteful number, since it uses less digits than its factorization.

1221311310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40710387.

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

The square root of 1221311310 is about 34947.2646998302. The cubic root of 1221311310 is about 1068.9124274181.

Adding to 1221311310 its reverse (131131221), we get a palindrome (1352442531).

The spelling of 1221311310 in words is "one billion, two hundred twenty-one million, three hundred eleven thousand, three hundred ten".