1213665 has 8 divisors (see below), whose sum is σ = 1941888. Its totient is φ = 647280.

The previous prime is 1213661. The next prime is 1213673. The reversal of 1213665 is 5663121.

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

It is not a de Polignac number, because 1213665 - 2² = 1213661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213661) 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, 40441 + ... + 40470.

It is an arithmetic number, because the mean of its divisors is an integer number (242736).

2^1213665 is an apocalyptic number.

1213665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1213665 is a deficient number, since it is larger than the sum of its proper divisors (728223).

1213665 is an equidigital number, since it uses as much as digits as its factorization.

1213665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80919.

The product of its digits is 1080, while the sum is 24.

The square root of 1213665 is about 1101.6646495191. The cubic root of 1213665 is about 106.6677028979.

Adding to 1213665 its reverse (5663121), we get a palindrome (6876786).

The spelling of 1213665 in words is "one million, two hundred thirteen thousand, six hundred sixty-five".