400009122 has 24 divisors (see below), whose sum is σ = 896573340. Its totient is φ = 128738400.

The previous prime is 400009097. The next prime is 400009163. The reversal of 400009122 is 221900004.

It can be written as a sum of positive squares in 2 ways, for example, as 346294881 + 53714241 = 18609^2 + 7329^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 400009095 and 400009104.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 382629 + ... + 383672.

Almost surely, 2^400009122 is an apocalyptic number.

400009122 is an abundant number, since it is smaller than the sum of its proper divisors (496564218).

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

400009122 is a wasteful number, since it uses less digits than its factorization.

400009122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766338 (or 766335 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 400009122 is about 20000.2280486998. The cubic root of 400009122 is about 736.8119006414.

Adding to 400009122 its reverse (221900004), we get a palindrome (621909126).

The spelling of 400009122 in words is "four hundred million, nine thousand, one hundred twenty-two".