402442181 has 2 divisors, whose sum is σ = 402442182. Its totient is φ = 402442180.

The previous prime is 402442177. The next prime is 402442219. The reversal of 402442181 is 181244204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 287845156 + 114597025 = 16966^2 + 10705^2 .

It is a cyclic number.

It is not a de Polignac number, because 402442181 - 2² = 402442177 is a prime.

It is a super-2 number, since 2×402442181² = 323919418096073522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 402442181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402442141) 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 as a sum of consecutive naturals, namely, 201221090 + 201221091.

It is an arithmetic number, because the mean of its divisors is an integer number (201221091).

Almost surely, 2^402442181 is an apocalyptic number.

It is an amenable number.

402442181 is a deficient number, since it is larger than the sum of its proper divisors (1).

402442181 is an equidigital number, since it uses as much as digits as its factorization.

402442181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2048, while the sum is 26.

The square root of 402442181 is about 20060.9616170312. The cubic root of 402442181 is about 738.3027702593.

Adding to 402442181 its reverse (181244204), we get a palindrome (583686385).

The spelling of 402442181 in words is "four hundred two million, four hundred forty-two thousand, one hundred eighty-one".