402440020 has 24 divisors (see below), whose sum is σ = 848824200. Its totient is φ = 160271232.

The previous prime is 402439951. The next prime is 402440023. The reversal of 402440020 is 20044204.

It can be written as a sum of positive squares in 4 ways, for example, as 33339076 + 369100944 = 5774^2 + 19212^2 .

It is a junction number, because it is equal to n+sod(n) for n = 402439976 and 402440003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402440023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39355 + ... + 48514.

It is an arithmetic number, because the mean of its divisors is an integer number (35367675).

Almost surely, 2^402440020 is an apocalyptic number.

It is an amenable number.

402440020 is an abundant number, since it is smaller than the sum of its proper divisors (446384180).

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

402440020 is a wasteful number, since it uses less digits than its factorization.

402440020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88107 (or 88105 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

The square root of 402440020 is about 20060.9077561311. The cubic root of 402440020 is about 738.3014487650.

Adding to 402440020 its reverse (20044204), we get a palindrome (422484224).

It can be divided in two parts, 4024 and 40020, that added together give a palindrome (44044).

The spelling of 402440020 in words is "four hundred two million, four hundred forty thousand, twenty".