1216651 has 4 divisors (see below), whose sum is σ = 1220400. Its totient is φ = 1212904.

The previous prime is 1216619. The next prime is 1216681. The reversal of 1216651 is 1566121.

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

It is a cyclic number.

It is not a de Polignac number, because 1216651 - 2⁵ = 1216619 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1216601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1336 + ... + 2053.

It is an arithmetic number, because the mean of its divisors is an integer number (305100).

2^1216651 is an apocalyptic number.

1216651 is a deficient number, since it is larger than the sum of its proper divisors (3749).

1216651 is an equidigital number, since it uses as much as digits as its factorization.

1216651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3748.

The product of its digits is 360, while the sum is 22.

The square root of 1216651 is about 1103.0190388203. The cubic root of 1216651 is about 106.7551100231.

The spelling of 1216651 in words is "one million, two hundred sixteen thousand, six hundred fifty-one".