20409408 has 140 divisors (see below), whose sum is σ = 62943232. Its totient is φ = 6531840.

The previous prime is 20409383. The next prime is 20409437. The reversal of 20409408 is 80490402.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 160641 + ... + 160767.

Almost surely, 2^20409408 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 20409408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31471616).

20409408 is an abundant number, since it is smaller than the sum of its proper divisors (42533824).

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

20409408 is a wasteful number, since it uses less digits than its factorization.

20409408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 20409408 is about 4517.6772793107. The cubic root of 20409408 is about 273.2814390211.

The spelling of 20409408 in words is "twenty million, four hundred nine thousand, four hundred eight".