1216745 has 8 divisors (see below), whose sum is σ = 1499784. Its totient is φ = 946944.

The previous prime is 1216729. The next prime is 1216751. The reversal of 1216745 is 5476121.

1216745 = T₉ + T₁₀ + ... + T₁₉₃.

It can be written as a sum of positive squares in 4 ways, for example, as 737881 + 478864 = 859^2 + 692^2 .

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 1216745 - 2⁴ = 1216729 is a prime.

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

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3104 + ... + 3473.

It is an arithmetic number, because the mean of its divisors is an integer number (187473).

2^1216745 is an apocalyptic number.

It is an amenable number.

1216745 is a deficient number, since it is larger than the sum of its proper divisors (283039).

1216745 is an equidigital number, since it uses as much as digits as its factorization.

1216745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6619.

The product of its digits is 1680, while the sum is 26.

The square root of 1216745 is about 1103.0616483225. The cubic root of 1216745 is about 106.7578592974.

The spelling of 1216745 in words is "one million, two hundred sixteen thousand, seven hundred forty-five".