402321218 has 16 divisors (see below), whose sum is σ = 688133880. Its totient is φ = 174763776.

The previous prime is 402321217. The next prime is 402321223. The reversal of 402321218 is 812123204.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 349802209 + 52519009 = 18703^2 + 7247^2 .

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 402321193 and 402321202.

It is not an unprimeable number, because it can be changed into a prime (402321211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 454673 + ... + 455556.

Almost surely, 2^402321218 is an apocalyptic number.

402321218 is a deficient number, since it is larger than the sum of its proper divisors (285812662).

402321218 is a wasteful number, since it uses less digits than its factorization.

402321218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910261.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 402321218 is about 20057.9465050638. The cubic root of 402321218 is about 738.2287917091.

The spelling of 402321218 in words is "four hundred two million, three hundred twenty-one thousand, two hundred eighteen".