400401331 has 4 divisors (see below), whose sum is σ = 436801464. Its totient is φ = 364001200.

The previous prime is 400401329. The next prime is 400401343. The reversal of 400401331 is 133104004.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 400401331 - 2¹ = 400401329 is a prime.

It is a super-2 number, since 2×400401331² = 320642451733143122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (400401311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18200050 + ... + 18200071.

It is an arithmetic number, because the mean of its divisors is an integer number (109200366).

Almost surely, 2^400401331 is an apocalyptic number.

400401331 is a deficient number, since it is larger than the sum of its proper divisors (36400133).

400401331 is a wasteful number, since it uses less digits than its factorization.

400401331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36400132.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 400401331 is about 20010.0307595965. The cubic root of 400401331 is about 737.0526367018.

Adding to 400401331 its reverse (133104004), we get a palindrome (533505335).

The spelling of 400401331 in words is "four hundred million, four hundred one thousand, three hundred thirty-one".