1225819218 has 16 divisors (see below), whose sum is σ = 2640226176. Its totient is φ = 377175120.

The previous prime is 1225819211. The next prime is 1225819253. The reversal of 1225819218 is 8129185221.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (1225819211) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7857738 + ... + 7857893.

It is an arithmetic number, because the mean of its divisors is an integer number (165014136).

Almost surely, 2^1225819218 is an apocalyptic number.

1225819218 is an abundant number, since it is smaller than the sum of its proper divisors (1414406958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1225819218 is a wasteful number, since it uses less digits than its factorization.

1225819218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15715649.

The product of its digits is 23040, while the sum is 39.

The square root of 1225819218 is about 35011.7011583271. The cubic root of 1225819218 is about 1070.2259452395.

The spelling of 1225819218 in words is "one billion, two hundred twenty-five million, eight hundred nineteen thousand, two hundred eighteen".