1221567 has 16 divisors (see below), whose sum is σ = 1776000. Its totient is φ = 743904.

The previous prime is 1221559. The next prime is 1221589. The reversal of 1221567 is 7651221.

It is not a de Polignac number, because 1221567 - 2³ = 1221559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1284 + ... + 2022.

It is an arithmetic number, because the mean of its divisors is an integer number (111000).

2^1221567 is an apocalyptic number.

1221567 is a deficient number, since it is larger than the sum of its proper divisors (554433).

1221567 is a wasteful number, since it uses less digits than its factorization.

1221567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790.

The product of its digits is 840, while the sum is 24.

The square root of 1221567 is about 1105.2452216590. The cubic root of 1221567 is about 106.8987016958.

Adding to 1221567 its reverse (7651221), we get a palindrome (8872788).

The spelling of 1221567 in words is "one million, two hundred twenty-one thousand, five hundred sixty-seven".