402008405 has 4 divisors (see below), whose sum is σ = 482410092. Its totient is φ = 321606720.

The previous prime is 402008393. The next prime is 402008413. The reversal of 402008405 is 504800204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 274001809 + 128006596 = 16553^2 + 11314^2 .

It is not a de Polignac number, because 402008405 - 2⁴ = 402008389 is a prime.

It is a super-2 number, since 2×402008405² = 323221515381288050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 40200836 + ... + 40200845.

It is an arithmetic number, because the mean of its divisors is an integer number (120602523).

Almost surely, 2^402008405 is an apocalyptic number.

It is an amenable number.

402008405 is a deficient number, since it is larger than the sum of its proper divisors (80401687).

402008405 is an equidigital number, since it uses as much as digits as its factorization.

402008405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80401686.

The product of its (nonzero) digits is 1280, while the sum is 23.

The square root of 402008405 is about 20050.1472563171. The cubic root of 402008405 is about 738.0374127571.

Adding to 402008405 its reverse (504800204), we get a palindrome (906808609).

The spelling of 402008405 in words is "four hundred two million, eight thousand, four hundred five".