1220287 has 4 divisors (see below), whose sum is σ = 1231200. Its totient is φ = 1209376.

The previous prime is 1220257. The next prime is 1220309. The reversal of 1220287 is 7820221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7820221 = 17 ⋅460013.

It is a cyclic number.

It is not a de Polignac number, because 1220287 - 2¹⁹ = 695999 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 (1220257) 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, 5287 + ... + 5512.

It is an arithmetic number, because the mean of its divisors is an integer number (307800).

2^1220287 is an apocalyptic number.

1220287 is a deficient number, since it is larger than the sum of its proper divisors (10913).

1220287 is a wasteful number, since it uses less digits than its factorization.

1220287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10912.

The product of its (nonzero) digits is 448, while the sum is 22.

The square root of 1220287 is about 1104.6660128745. Note that the first 3 decimals coincide. The cubic root of 1220287 is about 106.8613512659.

The spelling of 1220287 in words is "one million, two hundred twenty thousand, two hundred eighty-seven".