1216649 has 4 divisors (see below), whose sum is σ = 1390464. Its totient is φ = 1042836.

The previous prime is 1216619. The next prime is 1216681. The reversal of 1216649 is 9466121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1216649 - 2⁸ = 1216393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216619) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86897 + ... + 86910.

It is an arithmetic number, because the mean of its divisors is an integer number (347616).

2^1216649 is an apocalyptic number.

It is an amenable number.

1216649 is a deficient number, since it is larger than the sum of its proper divisors (173815).

1216649 is an equidigital number, since it uses as much as digits as its factorization.

1216649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173814.

The product of its digits is 2592, while the sum is 29.

The square root of 1216649 is about 1103.0181322172. The cubic root of 1216649 is about 106.7550515264.

It can be divided in two parts, 12 and 16649, that added together give a palindrome (16661).

The spelling of 1216649 in words is "one million, two hundred sixteen thousand, six hundred forty-nine".