1216858 has 4 divisors (see below), whose sum is σ = 1825290. Its totient is φ = 608428.

The previous prime is 1216849. The next prime is 1216867. The reversal of 1216858 is 8586121.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (1216849) and next prime (1216867).

It can be written as a sum of positive squares in only one way, i.e., 1067089 + 149769 = 1033^2 + 387^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304213 + ... + 304216.

2^1216858 is an apocalyptic number.

1216858 is a deficient number, since it is larger than the sum of its proper divisors (608432).

1216858 is an equidigital number, since it uses as much as digits as its factorization.

1216858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 608431.

The product of its digits is 3840, while the sum is 31.

The square root of 1216858 is about 1103.1128682052. The cubic root of 1216858 is about 106.7611640886.

The spelling of 1216858 in words is "one million, two hundred sixteen thousand, eight hundred fifty-eight".