400021361 has 2 divisors, whose sum is σ = 400021362. Its totient is φ = 400021360.

The previous prime is 400021333. The next prime is 400021367. The reversal of 400021361 is 163120004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 393030625 + 6990736 = 19825^2 + 2644^2 .

It is a cyclic number.

It is not a de Polignac number, because 400021361 - 2¹⁴ = 400004977 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (400021367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200010680 + 200010681.

It is an arithmetic number, because the mean of its divisors is an integer number (200010681).

Almost surely, 2^400021361 is an apocalyptic number.

It is an amenable number.

400021361 is a deficient number, since it is larger than the sum of its proper divisors (1).

400021361 is an equidigital number, since it uses as much as digits as its factorization.

400021361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 400021361 is about 20000.5340178706. The cubic root of 400021361 is about 736.8194152608.

Adding to 400021361 its reverse (163120004), we get a palindrome (563141365).

The spelling of 400021361 in words is "four hundred million, twenty-one thousand, three hundred sixty-one".