400431643 has 8 divisors (see below), whose sum is σ = 407631600. Its totient is φ = 393245568.

The previous prime is 400431607. The next prime is 400431667. The reversal of 400431643 is 346134004.

It is a happy number.

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 400431643 - 2²¹ = 398334491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400431943) 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, 67543 + ... + 73231.

It is an arithmetic number, because the mean of its divisors is an integer number (50953950).

Almost surely, 2^400431643 is an apocalyptic number.

400431643 is a deficient number, since it is larger than the sum of its proper divisors (7199957).

400431643 is a wasteful number, since it uses less digits than its factorization.

400431643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6941.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 400431643 is about 20010.7881653872. The cubic root of 400431643 is about 737.0712355209.

Adding to 400431643 its reverse (346134004), we get a palindrome (746565647).

The spelling of 400431643 in words is "four hundred million, four hundred thirty-one thousand, six hundred forty-three".