1220647 has 4 divisors (see below), whose sum is σ = 1223776. Its totient is φ = 1217520.

The previous prime is 1220623. The next prime is 1220657. The reversal of 1220647 is 7460221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7460221 = 29 ⋅257249.

It is a cyclic number.

It is not a de Polignac number, because 1220647 - 2¹⁹ = 696359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220657) 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, 879 + ... + 1792.

It is an arithmetic number, because the mean of its divisors is an integer number (305944).

2^1220647 is an apocalyptic number.

1220647 is a deficient number, since it is larger than the sum of its proper divisors (3129).

1220647 is an equidigital number, since it uses as much as digits as its factorization.

1220647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3128.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 1220647 is about 1104.8289460364. The cubic root of 1220647 is about 106.8718587132.

Adding to 1220647 its reverse (7460221), we get a palindrome (8680868).

The spelling of 1220647 in words is "one million, two hundred twenty thousand, six hundred forty-seven".