400209457 has 2 divisors, whose sum is σ = 400209458. Its totient is φ = 400209456.

The previous prime is 400209451. The next prime is 400209479. The reversal of 400209457 is 754902004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 394260736 + 5948721 = 19856^2 + 2439^2 .

It is a cyclic number.

It is not a de Polignac number, because 400209457 - 2²⁷ = 265991729 is a prime.

It is not a weakly prime, because it can be changed into another prime (400209451) 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, 200104728 + 200104729.

It is an arithmetic number, because the mean of its divisors is an integer number (200104729).

Almost surely, 2^400209457 is an apocalyptic number.

It is an amenable number.

400209457 is a deficient number, since it is larger than the sum of its proper divisors (1).

400209457 is an equidigital number, since it uses as much as digits as its factorization.

400209457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 400209457 is about 20005.2357396758. The cubic root of 400209457 is about 736.9348849841.

The spelling of 400209457 in words is "four hundred million, two hundred nine thousand, four hundred fifty-seven".