409238820 has 36 divisors (see below), whose sum is σ = 1241358300. Its totient is φ = 109130304.

The previous prime is 409238789. The next prime is 409238827. The reversal of 409238820 is 28832904.

It can be written as a sum of positive squares in 2 ways, for example, as 316270656 + 92968164 = 17784^2 + 9642^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (409238827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1136595 + ... + 1136954.

It is an arithmetic number, because the mean of its divisors is an integer number (34482175).

Almost surely, 2^409238820 is an apocalyptic number.

It is an amenable number.

409238820 is an abundant number, since it is smaller than the sum of its proper divisors (832119480).

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

409238820 is a wasteful number, since it uses less digits than its factorization.

409238820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2273564 (or 2273559 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 409238820 is about 20229.6519989841. The cubic root of 409238820 is about 742.4358615482.

The spelling of 409238820 in words is "four hundred nine million, two hundred thirty-eight thousand, eight hundred twenty".