400120420 has 96 divisors (see below), whose sum is σ = 1007774208. Its totient is φ = 130470912.

The previous prime is 400120387. The next prime is 400120421. The reversal of 400120420 is 24021004.

It is a self number, because there is not a number n which added to its sum of digits gives 400120420.

It is not an unprimeable number, because it can be changed into a prime (400120421) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1007662 + ... + 1008058.

It is an arithmetic number, because the mean of its divisors is an integer number (10497648).

Almost surely, 2^400120420 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400120420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (503887104).

400120420 is an abundant number, since it is smaller than the sum of its proper divisors (607653788).

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

400120420 is a wasteful number, since it uses less digits than its factorization.

400120420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 749 (or 747 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 400120420 is about 20003.0102734563. The cubic root of 400120420 is about 736.8802308218.

Adding to 400120420 its reverse (24021004), we get a palindrome (424141424).

The spelling of 400120420 in words is "four hundred million, one hundred twenty thousand, four hundred twenty".