400000042 has 8 divisors (see below), whose sum is σ = 646153956. Its totient is φ = 184615392.

The previous prime is 400000009. The next prime is 400000043. The reversal of 400000042 is 240000004.

It can be written as a sum of positive squares in 2 ways, for example, as 277255801 + 122744241 = 16651^2 + 11079^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 399999974 and 400000028.

It is not an unprimeable number, because it can be changed into a prime (400000043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7692283 + ... + 7692334.

Almost surely, 2^400000042 is an apocalyptic number.

400000042 is a deficient number, since it is larger than the sum of its proper divisors (246153914).

400000042 is a wasteful number, since it uses less digits than its factorization.

400000042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15384632.

The product of its (nonzero) digits is 32, while the sum is 10.

The square root of 400000042 is about 20000.0010500000. The cubic root of 400000042 is about 736.8063255163.

Adding to 400000042 its reverse (240000004), we get a palindrome (640000046).

It can be divided in two parts, 40000004 and 2, that multiplied together give a palindrome (80000008).

The spelling of 400000042 in words is "four hundred million, forty-two", and thus it is an aban number.