1221263 has 12 divisors (see below), whose sum is σ = 1371600. Its totient is φ = 1083456.

The previous prime is 1221251. The next prime is 1221289. The reversal of 1221263 is 3621221.

It is not a de Polignac number, because 1221263 - 2⁴ = 1221247 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221223) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6038 + ... + 6236.

It is an arithmetic number, because the mean of its divisors is an integer number (114300).

2^1221263 is an apocalyptic number.

1221263 is a deficient number, since it is larger than the sum of its proper divisors (150337).

1221263 is a wasteful number, since it uses less digits than its factorization.

1221263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 254 (or 235 counting only the distinct ones).

The product of its digits is 144, while the sum is 17.

The square root of 1221263 is about 1105.1076870604. The cubic root of 1221263 is about 106.8898333321.

Adding to 1221263 its reverse (3621221), we get a palindrome (4842484).

It can be divided in two parts, 1221 and 263, that multiplied together give a palindrome (321123).

The spelling of 1221263 in words is "one million, two hundred twenty-one thousand, two hundred sixty-three".