1221872 has 10 divisors (see below), whose sum is σ = 2367408. Its totient is φ = 610928.

The previous prime is 1221863. The next prime is 1221907. The reversal of 1221872 is 2781221.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38168 + ... + 38199.

2^1221872 is an apocalyptic number.

It is an amenable number.

1221872 is a deficient number, since it is larger than the sum of its proper divisors (1145536).

1221872 is an equidigital number, since it uses as much as digits as its factorization.

1221872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76375 (or 76369 counting only the distinct ones).

The product of its digits is 448, while the sum is 23.

The square root of 1221872 is about 1105.3831914771. The cubic root of 1221872 is about 106.9075977534.

The spelling of 1221872 in words is "one million, two hundred twenty-one thousand, eight hundred seventy-two".