400406520 has 128 divisors (see below), whose sum is σ = 1234751040. Its totient is φ = 103833600.

The previous prime is 400406483. The next prime is 400406537. The reversal of 400406520 is 25604004.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 998320 + ... + 998720.

Almost surely, 2^400406520 is an apocalyptic number.

400406520 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400406520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (617375520).

400406520 is an abundant number, since it is smaller than the sum of its proper divisors (834344520).

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

400406520 is a wasteful number, since it uses less digits than its factorization.

400406520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 625 (or 621 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 400406520 is about 20010.1604191471. The cubic root of 400406520 is about 737.0558206319.

The spelling of 400406520 in words is "four hundred million, four hundred six thousand, five hundred twenty".