1228781 has 4 divisors (see below), whose sum is σ = 1232064. Its totient is φ = 1225500.

The previous prime is 1228763. The next prime is 1228783. The reversal of 1228781 is 1878221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1228781 - 2¹⁴ = 1212397 is a prime.

It is a super-2 number, since 2×1228781² = 3019805491922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1228783) 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, 995 + ... + 1856.

It is an arithmetic number, because the mean of its divisors is an integer number (308016).

2^1228781 is an apocalyptic number.

It is an amenable number.

1228781 is a deficient number, since it is larger than the sum of its proper divisors (3283).

1228781 is an equidigital number, since it uses as much as digits as its factorization.

1228781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3282.

The product of its digits is 1792, while the sum is 29.

The square root of 1228781 is about 1108.5039467679. The cubic root of 1228781 is about 107.1087199606.

The spelling of 1228781 in words is "one million, two hundred twenty-eight thousand, seven hundred eighty-one".