400320042 has 48 divisors (see below), whose sum is σ = 826822080. Its totient is φ = 129193152.

The previous prime is 400320017. The next prime is 400320047. The reversal of 400320042 is 240023004.

It is a happy number.

It is a super-2 number, since 2×400320042² = 320512272053763528, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (400320047) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2397043 + ... + 2397209.

It is an arithmetic number, because the mean of its divisors is an integer number (17225460).

Almost surely, 2^400320042 is an apocalyptic number.

400320042 is an abundant number, since it is smaller than the sum of its proper divisors (426502038).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

400320042 is a wasteful number, since it uses less digits than its factorization.

400320042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 15.

The square root of 400320042 is about 20007.9994502199. Note that the first 3 decimals coincide. The cubic root of 400320042 is about 737.0027548106.

Adding to 400320042 its reverse (240023004), we get a palindrome (640343046).

The spelling of 400320042 in words is "four hundred million, three hundred twenty thousand, forty-two".