1221867 has 12 divisors (see below), whose sum is σ = 1780480. Its totient is φ = 807408.

The previous prime is 1221863. The next prime is 1221907. The reversal of 1221867 is 7681221.

It is not a de Polignac number, because 1221867 - 2² = 1221863 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221867.

It is not an unprimeable number, because it can be changed into a prime (1221863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 609 + ... + 1677.

2^1221867 is an apocalyptic number.

1221867 is a deficient number, since it is larger than the sum of its proper divisors (558613).

1221867 is a wasteful number, since it uses less digits than its factorization.

1221867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1202 (or 1199 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 1221867 is about 1105.3809298156. The cubic root of 1221867 is about 106.9074519283.

The spelling of 1221867 in words is "one million, two hundred twenty-one thousand, eight hundred sixty-seven".