400021734 has 16 divisors (see below), whose sum is σ = 914335488. Its totient is φ = 114291912.

The previous prime is 400021729. The next prime is 400021753. The reversal of 400021734 is 437120004.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 400021734.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 4762122 + ... + 4762205.

It is an arithmetic number, because the mean of its divisors is an integer number (57145968).

Almost surely, 2^400021734 is an apocalyptic number.

400021734 is an abundant number, since it is smaller than the sum of its proper divisors (514313754).

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

400021734 is a wasteful number, since it uses less digits than its factorization.

400021734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9524339.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 400021734 is about 20000.5433426195. The cubic root of 400021734 is about 736.8196442765.

Adding to 400021734 its reverse (437120004), we get a palindrome (837141738).

The spelling of 400021734 in words is "four hundred million, twenty-one thousand, seven hundred thirty-four".