402311281 has 2 divisors, whose sum is σ = 402311282. Its totient is φ = 402311280.

The previous prime is 402311279. The next prime is 402311291. The reversal of 402311281 is 182113204.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 391683681 + 10627600 = 19791^2 + 3260^2 .

It is a cyclic number.

It is not a de Polignac number, because 402311281 - 2¹ = 402311279 is a prime.

It is a super-2 number, since 2×402311281² = 323708733639721922, which contains 22 as substring.

Together with 402311279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (402311251) 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 as a sum of consecutive naturals, namely, 201155640 + 201155641.

It is an arithmetic number, because the mean of its divisors is an integer number (201155641).

Almost surely, 2^402311281 is an apocalyptic number.

It is an amenable number.

402311281 is a deficient number, since it is larger than the sum of its proper divisors (1).

402311281 is an equidigital number, since it uses as much as digits as its factorization.

402311281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 402311281 is about 20057.6987962229. The cubic root of 402311281 is about 738.2227137796. Note that the first 3 decimals are identical.

Adding to 402311281 its reverse (182113204), we get a palindrome (584424485).

The spelling of 402311281 in words is "four hundred two million, three hundred eleven thousand, two hundred eighty-one".