402243421 has 4 divisors (see below), whose sum is σ = 406763100. Its totient is φ = 397723744.

The previous prime is 402243419. The next prime is 402243451. The reversal of 402243421 is 124342204.

It is a happy number.

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 125686521 + 276556900 = 11211^2 + 16630^2 .

It is a cyclic number.

It is not a de Polignac number, because 402243421 - 2¹ = 402243419 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 402243392 and 402243401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402243451) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2259706 + ... + 2259883.

It is an arithmetic number, because the mean of its divisors is an integer number (101690775).

Almost surely, 2^402243421 is an apocalyptic number.

It is an amenable number.

402243421 is a deficient number, since it is larger than the sum of its proper divisors (4519679).

402243421 is an equidigital number, since it uses as much as digits as its factorization.

402243421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4519678.

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 402243421 is about 20056.0071051044. The cubic root of 402243421 is about 738.1812047851.

Adding to 402243421 its reverse (124342204), we get a palindrome (526585625).

The spelling of 402243421 in words is "four hundred two million, two hundred forty-three thousand, four hundred twenty-one".