400340261 has 2 divisors, whose sum is σ = 400340262. Its totient is φ = 400340260.

The previous prime is 400340201. The next prime is 400340329. The reversal of 400340261 is 162043004.

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., 231496225 + 168844036 = 15215^2 + 12994^2 .

It is a cyclic number.

It is not a de Polignac number, because 400340261 - 2¹⁰ = 400339237 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400340201) 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, 200170130 + 200170131.

It is an arithmetic number, because the mean of its divisors is an integer number (200170131).

Almost surely, 2^400340261 is an apocalyptic number.

It is an amenable number.

400340261 is a deficient number, since it is larger than the sum of its proper divisors (1).

400340261 is an equidigital number, since it uses as much as digits as its factorization.

400340261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 400340261 is about 20008.5047167448. The cubic root of 400340261 is about 737.0151625563.

Adding to 400340261 its reverse (162043004), we get a palindrome (562383265).

The spelling of 400340261 in words is "four hundred million, three hundred forty thousand, two hundred sixty-one".