1216565 has 8 divisors (see below), whose sum is σ = 1668480. Its totient is φ = 834192.

The previous prime is 1216561. The next prime is 1216577. The reversal of 1216565 is 5656121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1216565 - 2² = 1216561 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216561) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17345 + ... + 17414.

It is an arithmetic number, because the mean of its divisors is an integer number (208560).

2^1216565 is an apocalyptic number.

It is an amenable number.

1216565 is a deficient number, since it is larger than the sum of its proper divisors (451915).

1216565 is an equidigital number, since it uses as much as digits as its factorization.

1216565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34771.

The product of its digits is 1800, while the sum is 26.

The square root of 1216565 is about 1102.9800542168. The cubic root of 1216565 is about 106.7525946055.

The spelling of 1216565 in words is "one million, two hundred sixteen thousand, five hundred sixty-five".