402221665 has 8 divisors (see below), whose sum is σ = 482998248. Its totient is φ = 321555840.

The previous prime is 402221657. The next prime is 402221669. The reversal of 402221665 is 566122204.

It can be written as a sum of positive squares in 4 ways, for example, as 109914256 + 292307409 = 10484^2 + 17097^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 402221665 - 2³ = 402221657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402221669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19476 + ... + 34405.

It is an arithmetic number, because the mean of its divisors is an integer number (60374781).

Almost surely, 2^402221665 is an apocalyptic number.

It is an amenable number.

402221665 is a deficient number, since it is larger than the sum of its proper divisors (80776583).

402221665 is a wasteful number, since it uses less digits than its factorization.

402221665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55379.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 402221665 is about 20055.4647166302. The cubic root of 402221665 is about 738.1678959618.

Adding to 402221665 its reverse (566122204), we get a palindrome (968343869).

The spelling of 402221665 in words is "four hundred two million, two hundred twenty-one thousand, six hundred sixty-five".