400040401 has 4 divisors (see below), whose sum is σ = 400081204. Its totient is φ = 399999600.

The previous prime is 400040393. The next prime is 400040419. The reversal of 400040401 is 104040004.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 40401 + 400000000 = 201^2 + 20000^2 .

It is a cyclic number.

It is not a de Polignac number, because 400040401 - 2³ = 400040393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400040441) 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, 4171 + ... + 28591.

It is an arithmetic number, because the mean of its divisors is an integer number (100020301).

Almost surely, 2^400040401 is an apocalyptic number.

It is an amenable number.

400040401 is a deficient number, since it is larger than the sum of its proper divisors (40803).

400040401 is a wasteful number, since it uses less digits than its factorization.

400040401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40802.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 400040401 is about 20001.0099994975. The cubic root of 400040401 is about 736.8311053190.

Adding to 400040401 its reverse (104040004), we get a palindrome (504080405).

The spelling of 400040401 in words is "four hundred million, forty thousand, four hundred one".