1221391804 has 24 divisors (see below), whose sum is σ = 2226697200. Its totient is φ = 585697920.

The previous prime is 1221391789. The next prime is 1221391817. The reversal of 1221391804 is 4081931221.

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 7 ways as a sum of consecutive naturals, for example, 53439 + ... + 72790.

It is an arithmetic number, because the mean of its divisors is an integer number (92779050).

Almost surely, 2^1221391804 is an apocalyptic number.

It is an amenable number.

1221391804 is a deficient number, since it is larger than the sum of its proper divisors (1005305396).

1221391804 is a wasteful number, since it uses less digits than its factorization.

1221391804 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126333 (or 126331 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1221391804 is about 34948.4163303575. The cubic root of 1221391804 is about 1068.9359101415.

The spelling of 1221391804 in words is "one billion, two hundred twenty-one million, three hundred ninety-one thousand, eight hundred four".