400082509 has 2 divisors, whose sum is σ = 400082510. Its totient is φ = 400082508.

The previous prime is 400082479. The next prime is 400082519. The reversal of 400082509 is 905280004.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 399880009 + 202500 = 19997^2 + 450^2 .

It is a cyclic number.

It is not a de Polignac number, because 400082509 - 2⁷ = 400082381 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 (400082519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200041254 + 200041255.

It is an arithmetic number, because the mean of its divisors is an integer number (200041255).

Almost surely, 2^400082509 is an apocalyptic number.

It is an amenable number.

400082509 is a deficient number, since it is larger than the sum of its proper divisors (1).

400082509 is an equidigital number, since it uses as much as digits as its factorization.

400082509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 400082509 is about 20002.0626186401. The cubic root of 400082509 is about 736.8569572043.

The spelling of 400082509 in words is "four hundred million, eighty-two thousand, five hundred nine".