1221591064228 has 24 divisors (see below), whose sum is σ = 2187865310400. Its totient is φ = 596618569248.

The previous prime is 1221591064219. The next prime is 1221591064277. The reversal of 1221591064228 is 8224601951221.

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, 16447768 + ... + 16521871.

It is an arithmetic number, because the mean of its divisors is an integer number (91161054600).

Almost surely, 2^{1221591064228} is an apocalyptic number.

It is an amenable number.

1221591064228 is a deficient number, since it is larger than the sum of its proper divisors (966274246172).

1221591064228 is a wasteful number, since it uses less digits than its factorization.

1221591064228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32969859 (or 32969857 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 43.

The spelling of 1221591064228 in words is "one trillion, two hundred twenty-one billion, five hundred ninety-one million, sixty-four thousand, two hundred twenty-eight".