400328261 has 2 divisors, whose sum is σ = 400328262. Its totient is φ = 400328260.

The previous prime is 400328171. The next prime is 400328263. The reversal of 400328261 is 162823004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 244328161 + 156000100 = 15631^2 + 12490^2 .

It is a cyclic number.

It is not a de Polignac number, because 400328261 - 2²² = 396133957 is a prime.

Together with 400328263, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 400328261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400328263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200164130 + 200164131.

It is an arithmetic number, because the mean of its divisors is an integer number (200164131).

Almost surely, 2^400328261 is an apocalyptic number.

It is an amenable number.

400328261 is a deficient number, since it is larger than the sum of its proper divisors (1).

400328261 is an equidigital number, since it uses as much as digits as its factorization.

400328261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 400328261 is about 20008.2048420142. The cubic root of 400328261 is about 737.0077985952.

The spelling of 400328261 in words is "four hundred million, three hundred twenty-eight thousand, two hundred sixty-one".