1221861310 has 16 divisors (see below), whose sum is σ = 2315106000. Its totient is φ = 463021056.

The previous prime is 1221861307. The next prime is 1221861317. The reversal of 1221861310 is 131681221.

It is a super-2 number, since 2×1221861310² = 2985890121749832200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221861317) by changing a digit.

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, 3215235 + ... + 3215614.

It is an arithmetic number, because the mean of its divisors is an integer number (144694125).

Almost surely, 2^1221861310 is an apocalyptic number.

1221861310 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221861310 is a deficient number, since it is larger than the sum of its proper divisors (1093244690).

1221861310 is a wasteful number, since it uses less digits than its factorization.

1221861310 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6430875.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 1221861310 is about 34955.1328133652. The cubic root of 1221861310 is about 1069.0728597887.

The spelling of 1221861310 in words is "one billion, two hundred twenty-one million, eight hundred sixty-one thousand, three hundred ten".