1221391333 has 16 divisors (see below), whose sum is σ = 1352557440. Its totient is φ = 1097046016.

The previous prime is 1221391331. The next prime is 1221391337. The reversal of 1221391333 is 3331931221.

It is a cyclic number.

It is not a de Polignac number, because 1221391333 - 2¹ = 1221391331 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221391331) 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 15 ways as a sum of consecutive naturals, for example, 179253 + ... + 185941.

It is an arithmetic number, because the mean of its divisors is an integer number (84534840).

Almost surely, 2^1221391333 is an apocalyptic number.

It is an amenable number.

1221391333 is a deficient number, since it is larger than the sum of its proper divisors (131166107).

1221391333 is a wasteful number, since it uses less digits than its factorization.

1221391333 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7196.

The product of its digits is 2916, while the sum is 28.

The square root of 1221391333 is about 34948.4095918541. The cubic root of 1221391333 is about 1068.9357727384.

The spelling of 1221391333 in words is "one billion, two hundred twenty-one million, three hundred ninety-one thousand, three hundred thirty-three".