1221221310 has 32 divisors (see below), whose sum is σ = 2932169760. Its totient is φ = 325521408.

The previous prime is 1221221279. The next prime is 1221221327. The reversal of 1221221310 is 131221221.

It is a super-2 number, since 2×1221221310² = 2982762975996232200, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 1221221310.

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 15 ways as a sum of consecutive naturals, for example, 77806 + ... + 92174.

It is an arithmetic number, because the mean of its divisors is an integer number (91630305).

Almost surely, 2^1221221310 is an apocalyptic number.

1221221310 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221221310 is an abundant number, since it is smaller than the sum of its proper divisors (1710948450).

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

1221221310 is a wasteful number, since it uses less digits than its factorization.

1221221310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17212.

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

The square root of 1221221310 is about 34945.9770216831. The cubic root of 1221221310 is about 1068.8861702630.

Adding to 1221221310 its reverse (131221221), we get a palindrome (1352442531).

The spelling of 1221221310 in words is "one billion, two hundred twenty-one million, two hundred twenty-one thousand, three hundred ten".