1221853311 has 48 divisors (see below), whose sum is σ = 2215549440. Its totient is φ = 632681280.

The previous prime is 1221853309. The next prime is 1221853343. The reversal of 1221853311 is 1133581221.

1221853311 is a `hidden beast` number, since 122 + 1 + 8 + 533 + 1 + 1 = 666.

It is not a de Polignac number, because 1221853311 - 2¹ = 1221853309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221853811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 5341 + ... + 49721.

It is an arithmetic number, because the mean of its divisors is an integer number (46157280).

Almost surely, 2^1221853311 is an apocalyptic number.

1221853311 is a deficient number, since it is larger than the sum of its proper divisors (993696129).

1221853311 is a wasteful number, since it uses less digits than its factorization.

1221853311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44436 (or 44433 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 1221853311 is about 34955.0183950745. The cubic root of 1221853311 is about 1069.0705268637.

The spelling of 1221853311 in words is "one billion, two hundred twenty-one million, eight hundred fifty-three thousand, three hundred eleven".