400009243 has 8 divisors (see below), whose sum is σ = 415539936. Its totient is φ = 384753600.

The previous prime is 400009237. The next prime is 400009249. The reversal of 400009243 is 342900004.

It is an interprime number because it is at equal distance from previous prime (400009237) and next prime (400009249).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 400009243 - 2²¹ = 397912091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400009249) 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 in 7 ways as a sum of consecutive naturals, for example, 65796 + ... + 71617.

It is an arithmetic number, because the mean of its divisors is an integer number (51942492).

Almost surely, 2^400009243 is an apocalyptic number.

400009243 is a deficient number, since it is larger than the sum of its proper divisors (15530693).

400009243 is a wasteful number, since it uses less digits than its factorization.

400009243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137525.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 400009243 is about 20000.2310736651. The cubic root of 400009243 is about 736.8119749349.

Adding to 400009243 its reverse (342900004), we get a palindrome (742909247).

The spelling of 400009243 in words is "four hundred million, nine thousand, two hundred forty-three".