400100020 has 24 divisors (see below), whose sum is σ = 840586824. Its totient is φ = 159968256.

The previous prime is 400100011. The next prime is 400100033. The reversal of 400100020 is 20001004.

It can be written as a sum of positive squares in 4 ways, for example, as 25522704 + 374577316 = 5052^2 + 19354^2 .

It is a junction number, because it is equal to n+sod(n) for n = 400099976 and 400100012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80652 + ... + 85468.

It is an arithmetic number, because the mean of its divisors is an integer number (35024451).

Almost surely, 2^400100020 is an apocalyptic number.

It is an amenable number.

400100020 is an abundant number, since it is smaller than the sum of its proper divisors (440486804).

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

400100020 is a wasteful number, since it uses less digits than its factorization.

400100020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8979 (or 8977 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 400100020 is about 20002.5003437070. The cubic root of 400100020 is about 736.8677074151.

Adding to 400100020 its reverse (20001004), we get a palindrome (420101024).

The spelling of 400100020 in words is "four hundred million, one hundred thousand, twenty".