20409450 has 48 divisors (see below), whose sum is σ = 51145536. Its totient is φ = 5385600.

The previous prime is 20409437. The next prime is 20409481. The reversal of 20409450 is 5490402.

It is a self number, because there is not a number n which added to its sum of digits gives 20409450.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14790 + ... + 16110.

It is an arithmetic number, because the mean of its divisors is an integer number (1065532).

Almost surely, 2^20409450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20409450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25572768).

20409450 is an abundant number, since it is smaller than the sum of its proper divisors (30736086).

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

20409450 is a wasteful number, since it uses less digits than its factorization.

20409450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1439 (or 1434 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 20409450 is about 4517.6819277147. The cubic root of 20409450 is about 273.2816264806.

Adding to 20409450 its reverse (5490402), we get a palindrome (25899852).

The spelling of 20409450 in words is "twenty million, four hundred nine thousand, four hundred fifty".