400021084 has 18 divisors (see below), whose sum is σ = 743639960. Its totient is φ = 188244672.

The previous prime is 400021081. The next prime is 400021147. The reversal of 400021084 is 480120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400021081) 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 5 ways as a sum of consecutive naturals, for example, 171864 + ... + 174175.

Almost surely, 2^400021084 is an apocalyptic number.

It is an amenable number.

400021084 is a deficient number, since it is larger than the sum of its proper divisors (343618876).

400021084 is a wasteful number, since it uses less digits than its factorization.

400021084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346077 (or 346058 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 400021084 is about 20000.5270930543. The cubic root of 400021084 is about 736.8192451873.

Adding to 400021084 its reverse (480120004), we get a palindrome (880141088).

The spelling of 400021084 in words is "four hundred million, twenty-one thousand, eighty-four".