1229881 has 3 divisors (see below), whose sum is σ = 1230991.
Its totient is φ = 1228772.
The previous prime is 1229873. The next prime is 1229897. The reversal of 1229881 is 1889221.
It is a happy number.
The square root of 1229881 is 1109.
It is a perfect power (a square), and thus also a powerful number.
It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.
It can be written as a sum of positive squares in only one way, i.e., 19881 + 1210000 = 141^2 + 1100^2
It is not a de Polignac number, because 1229881 - 23 = 1229873 is a prime.
It is a super-2 number, since 2×12298812 = 3025214548322, which contains 22 as substring.
It is a Duffinian number.
It is not an unprimeable number, because it can be changed into a prime (1229381) by changing a digit.
It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 555 + ... + 1663.
21229881 is an apocalyptic number.
1229881 is the 1109-th square number.
1229881 is the 555-th centered octagonal number.
It is an amenable number.
1229881 is a deficient number, since it is larger than the sum of its proper divisors (1110).
1229881 is an frugal number, since it uses more digits than its factorization.
1229881 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2218 (or 1109 counting only the distinct ones).
The product of its digits is 2304, while the sum is 31.
The cubic root of 1229881 is about 107.1406715321.
Multiplying 1229881 by its product of digits (2304), we get a square (2833645824 = 532322).
The spelling of 1229881 in words is "one million, two hundred twenty-nine thousand, eight hundred eighty-one".